diff --git a/EPIC_SFA_CURVE_AWARENESS.md b/EPIC_SFA_CURVE_AWARENESS.md
index df2cebe8a7..89744ed9bc 100644
--- a/EPIC_SFA_CURVE_AWARENESS.md
+++ b/EPIC_SFA_CURVE_AWARENESS.md
@@ -14,11 +14,12 @@
 > SPDX-License-Identifier: (EPL-2.0 OR EDL-1.0) AND CC0-1.0
 > Assisted-by: xAI Grok (grok-4.3)
 > Assisted-by: Claude (Opus-4.7)
+> Assisted-by: Cursor Grok (grok-4.6)
 > ```
 
-**Status:** Draft v4 (2026-08-15).
-**Source:** stacked PRs on `grootstebozewolf/jts` — [#7](https://github.com/grootstebozewolf/jts/pull/7) `feature/sfa-curve-rgr` → `master` (SFA/SQL-MM types, WKT, structural types); [#8](https://github.com/grootstebozewolf/jts/pull/8) `cursor/curve-perf-gate-45a0` → #7 (PERF-GATE + closed-form lasers). Tip of this retip: `488c48ba`. Intended merge: **#8 first, then #7**.
-**Origin (historical):** [`feature/sfa-curve-buffer-spike`](https://github.com/grootstebozewolf/jts/tree/feature/sfa-curve-buffer-spike) — Draft v3 of this epic and the 49-method spec class.
+**Status:** Draft v5 (2026-08-16).
+**Source:** Parent epic [locationtech/jts#1195](https://github.com/locationtech/jts/issues/1195). Fork work: [grootstebozewolf/jts#7](https://github.com/grootstebozewolf/jts/pull/7) `feature/sfa-curve-rgr`, tip `210f1b16` (merge of [#11](https://github.com/grootstebozewolf/jts/pull/11)). [#8](https://github.com/grootstebozewolf/jts/pull/8) PERF-GATE, [#10](https://github.com/grootstebozewolf/jts/pull/10) nested annulus (`92fdbb71`), and [#11](https://github.com/grootstebozewolf/jts/pull/11) odd-n tangent NSpan (`d8c5824f`) are **merged into #7**. Draft [#12](https://github.com/grootstebozewolf/jts/pull/12) (`3cc5f1a5`) stamps `H-SHELL-HOLE-CROSS` + `H-SHELL-HOLE-X`; draft [#13](https://github.com/grootstebozewolf/jts/pull/13) (`73703036`) stamps `H-ANNULUS-TANGENT`. Both drafts are stacked, not merged. Slack still 15%. No new public API.
+**Origin (historical):** [`feature/sfa-curve-buffer-spike`](https://github.com/grootstebozewolf/jts/tree/feature/sfa-curve-buffer-spike) — Draft v3 of this epic and the 49-method spec class. Draft v4 (2026-08-15, tip `488c48ba`) described #8 as the live stacked branch; that merge order is done.
 **Audience:** locationtech/jts maintainers and contributors. Lift verbatim into a GitHub Epic / Discussion.
 
 **Field contract (PERF-GATE):** Maintainable → Reliable → Faster. Take the curve path only if `t_laser ≤ 1.15 × t_chainsaw`. Do not loosen 15%. The overlay name is **OverlayNGCurve**, never *Curved*.
@@ -27,7 +28,9 @@
 
 Make JTS preserve OGC SFA / ISO 19125-2 curve geometries — `CIRCULARSTRING`, `COMPOUNDCURVE`, `CURVEPOLYGON`, `MULTICURVE`, `MULTISURFACE`, `TRIANGLE` — through every algorithm where the math is sound, instead of silently linearising to flat parents on the way in.
 
-`jts-curve` is no longer only a parse-and-WKT stand-in: types exist, WKT and WKB (codes 8–12) round-trip without densify, and a handful of closed-form lasers (overlay / relate / distance / hull / area / Hausdorff-in-TestBuilder) beat the chord baseline on certified shapes. `jts-core` still densifies on contact for everything that is not one of those subsets. This epic tracks the lift, operation by operation — full TAG vs closed-form subset, not “good enough as linearised”.
+Every circular pair that has a closed form has a kit. Everything else is a named miss and the chordsaw. We will not write a circular noder in this PR.
+
+`jts-curve` is no longer only a parse-and-WKT stand-in: types exist, WKT and WKB (codes 8–12) round-trip without densify, and a closed-form kit set (overlay / relate / distance / hull / area / Hausdorff-in-TestBuilder / LEC obstacle distance) beats the chord baseline on certified shapes. Public DHD still sees chords in general; Fréchet is still open. Overlay **OV-P1** has flipped: every circular pair with a closed form has a kit; remaining overlay work is named R2 misses, not a blank “CompoundCurve still open”. `jts-core` still densifies on contact for everything that is not one of those subsets. This epic tracks the lift, operation by operation — full TAG vs closed-form subset, not “good enough as linearised”. **Do not mark OV green** for the *full* TAG. Circular noder + arrangement is **OV-P2 / Bar 2** — a different epic; do not start it here.
 
 ## 2. Why
 
@@ -41,37 +44,41 @@ Make JTS preserve OGC SFA / ISO 19125-2 curve geometries — `CIRCULARSTRING`, `
 **In scope (this epic):**
 - Algorithms operating on the six SFA curve types in 2-D.
 - WKT round-trip with member structure (landed on #7).
-- **WKB ISO/OGC type codes 8–12** (landed on #8). CircularString, CompoundCurve, CurvePolygon, MultiCurve, MultiSurface. The old “1000-series” wording was the ISO Z/M *dimension offset* (`type + 1000/2000/3000` for Z / M / ZM), not the curve type codes. Core `WKBReader` switches 8–12 the way GEOS does; construction is delegated to `GeometryFactory`. Writer: `CurveWKBWriter` emits 8–12 (hook before instanceof). Core `WKBWriter` does not emit 8–12 unless that hook/subclass is used.
+- **WKB ISO/OGC type codes 8–12** (on #7 now; landed via #8). CircularString, CompoundCurve, CurvePolygon, MultiCurve, MultiSurface. The old “1000-series” wording was the ISO Z/M *dimension offset* (`type + 1000/2000/3000` for Z / M / ZM), not the curve type codes. Core `WKBReader` switches 8–12 the way GEOS does; construction is delegated to `GeometryFactory`. Writer: `CurveWKBWriter` emits 8–12 (hook before instanceof). Core `WKBWriter` does not emit 8–12 unless that hook/subclass is used.
 - TestBuilder rendering and drawing tools.
 
 **Deferred to sibling epics — explicitly tracked, not pretended-not-to-exist:**
 - 3-D solids (`POLYHEDRALSURFACE`, `TIN`). Their structural / drawing support landed in the spike for visualisation; no 3-D semantics here.
 - Elliptic arcs (`ELLIPSARC`) — JTS has no ellipse model; adding one is bigger than this epic.
 - Z / M ordinate interpolation across densified arcs (today they propagate from the 3 control points unchanged; every TAG that produces densified output should leave room for a future interpolation policy).
+- **OV-P2 / Bar 2** — circular noder + arrangement + general PLG / COV. Different epic. Do not start.
 
 ## 4. What's already landed
 
-### 4.1 On #7 / #8 since the spike (tip `488c48ba`)
+### 4.1 On #7 since the spike (tip `210f1b16`)
 
 | Bucket | Summary | TAG honesty |
 |---|---|---|
-| `feat:` / `fix:` | **WKB 8–12.** Core `WKBReader` first-class cases: CircularString = count+coords; CompoundCurve / CurvePolygon / MultiCurve / MultiSurface = count + child WKBs (CurvePolygon rings carry their own type). `GeometryFactory.createCircularString` / `createCompoundCurve(LineString[])` / `createCurvePolygon(LineString, LineString[])` / `createMultiCurve` / `createMultiSurface` — default throws; `CurveGeometryFactory` implements. `new WKBReader(new CurveGeometryFactory()).read(type8)` returns `CircularString`. `CurveWKBReader` is the no-arg convenience. Locked XDR hex for `CIRCULARSTRING (0 0, 5 5, 10 0)` unchanged. Disc `CurvePolygon` area still 25π after round-trip. No `toLinear` on that path. | WKB sibling from Draft v3 — **landed**. Not a new public I/O class beyond the factory surface + existing curve writer/reader convenience. |
-| `feat:` | **OverlayNGCurve Phase 0** (named Phase 0). Ratchet: **R0** envelope-disjoint skip; **R1** retention when one envelope covers; **R1.5** `CircularDiscOverlay` two-disc closed form (CAP lens / CUP blob / SUB crescent / XOR crescents; crossing nodes `(3.5, ±√12.75)`); **R1.6** `CircularDiscPolygonOverlay` disc vs hole-free plain polygon (line–circle clip; half-disc area `12.5π`). Reverse `plain.op(curve)`, reverse SUB, MultiCurve/MultiSurface dispatch, nested Multi envelope skip. | **OV partial** (closed-form subset). Not a general circular noder. CompoundCurve overlay and N-SS are still open. Do not mark OV green. |
+| `feat:` / `fix:` | **WKB 8–12.** Core `WKBReader` first-class cases: CircularString = count+coords; CompoundCurve / CurvePolygon / MultiCurve / MultiSurface = count + child WKBs (CurvePolygon rings carry their own type). `GeometryFactory.createCircularString` / `createCompoundCurve(LineString[])` / `createCurvePolygon(LineString, LineString[])` / `createMultiCurve` / `createMultiSurface` — default throws; `CurveGeometryFactory` implements. `new WKBReader(new CurveGeometryFactory()).read(type8)` returns `CircularString`. `CurveWKBReader` is the no-arg convenience. Locked XDR hex for `CIRCULARSTRING (0 0, 5 5, 10 0)` unchanged. Disc `CurvePolygon` area still 25π after round-trip. No `toLinear` on that path. | WKB sibling from Draft v3 — **landed on #7** (via #8). Not a new public I/O class beyond the factory surface + existing curve writer/reader convenience. |
+| `feat:` | **OverlayNGCurve kits.** **R0** envelope-disjoint skip; **R1** retention when one envelope covers; **R1.5** `CircularDiscOverlay` two-disc closed form (CAP lens / CUP blob / SUB crescent / XOR crescents; crossing nodes `(3.5, ±√12.75)`); **R1.6** `CircularDiscPolygonOverlay` disc vs hole-free plain polygon (line–circle clip; half-disc area `12.5π`); **R1.7** CompoundCurve-shell kits (two-node, two-shell, collinear, 0/1-node, even-n, tangent-odd NSpan, same-outer hole, different-outer punch); **R-LL** CircularString / lineal CompoundCurve vs LineString; **R-AA** two CircularStrings (or lineal CompoundCurve vs CircularString) at exact nodes. Reverse `plain.op(curve)`, reverse SUB, MultiCurve/MultiSurface dispatch, nested Multi envelope skip. **D4** nested annulus: `CIRCLE_5 \ CIRCLE_3` is exact area `16π`, covers `EEEE` / coveredBy `EE0E`. **OV-P1 flipped.** Remaining named R2: `H-SHELL-N-MIXED`, `H-SHELL-HOLE-CROSS`, `H-SHELL-HOLE-X`, `H-ANNULUS-TANGENT`. Circular noder + arrangement is **OV-P2 / Bar 2** — different epic; do not start. | **OV partial** (closed-form subset). OV-P1 flipped; do **not** mark the *full* OV TAG green. Not a general circular noder. Keep `test_OV_*`. |
 | `feat:` | **R-CONT** certified disc PIP (interior + boundary band) in `CurveExact`. | **R-CONT partial**. |
 | `feat:` | **R-PR DE-9IM** for disc vs Point, LineString, hole-free Polygon, and two discs. Point: interior `0F2FF1FF2`, boundary `FF20F1FF2`, exterior `FF2FF10F2`. Line: crossing `1F20F1102`, tangent `FF20F1102`, miss `FF2FF1102`, endpoint-interior `1020F1102`. Polygon: disjoint `FF2FF1212`, nested `212FF1FF2`, disc-in-square `2FF1FF212`, crossing `212101212`. Two discs: crossing `212101212`, disjoint `FF2FF1212`, nested `212FF1FF2` / `2FF1FF212`, ext tangent `FF2F01212`, int tangent `212F01FF2`, equal `2FFF1FFF2`. Finish slice: single-member MultiSurface both orders; `equalsTopo` on equal/crossing/rotated-control discs; full SFS table; `crosses` of two areas always false. Half-disc / CompoundCurve miss still null → linearise. | **R-PR partial**. Not “any combination of curved/flat”. Do not delete `test_R_PR_*` / `test_R_CONT_*`. |
 | `feat:` | Distance closed-form helpers in `CurveExact` (arc-to-segment, overlapping discs `nearestPoints` 0, `decideTolerance` arc-aware). | Helpers only. **D-PT / D-AA / D-OP** still describe the public `DistanceOp` TAG — keep those spec methods red. |
 | `feat:` | Disc / arc convex hull closed forms. | **H-CV partial**. **H-CC** still open. |
-| `feat:` | TestBuilder `CurveExactFns` Hausdorff laser. Public `DiscreteHausdorffDistance` still sees chords. | **D-HF half-red**. Keep the spec method. |
+| `feat:` | TestBuilder `CurveExactFns` Hausdorff laser. Public `DiscreteHausdorffDistance` still sees chords in general. `DiscreteHausdorffDistance` on #7 has closed-form for two pairs only: single-arc `CircularString` → single-segment `LineString` (apex √949/6 − 7/6 ≈ 3.967641), and two circular discs. A single-member `MultiSurface` of one disc is the same pair, not a third. Exact path skips densify; densify 0.05 is not the laser. Keep the spec `fail()`. D-HF honesty lives on draft [#45](https://github.com/grootstebozewolf/jts/pull/45). | **D-HF half-red**. Keep the spec method. |
+| `feat:` | Typed LEC obstacle distance (point / segment / polygon / arc / disc) and certified disc closed form. Other obstacle sets keep the grid. | **LEC partial**. The public TAG is wider; do not describe LEC as a blank open. |
 | `feat:` | Disc `CurvePolygon` area 25π. | **M-AREA-CP partial** (circular discs). Keep the spec method. |
 | `arch:` | PERF-GATE: identity/chord-path rows use `assertChordPath`; slack stays **15%** (`1.15`). | Contract, not a TAG. |
 
-These closed-form subsets of **OV** and **R-PR** did **not** wait for N-SS. Line–circle clip is used *inside* R1.6; there is still no public arc-arc / arc-line utility and no arc `SegmentString`.
+These closed-form subsets of **OV** and **R-PR** did **not** wait for N-SS. Line–circle clip is used *inside* R1.6; R-LL / R-AA are overlay kits, not a public arc-arc / arc-line utility and not an arc `SegmentString`.
 
 **Still open** (say so, do not close as “future work” a TAG that already has a named subset):
 
-- Public `DiscreteHausdorffDistance` (D-HF) — TestBuilder laser only
-- General circular noding / CompoundCurve overlay (N-AA, N-AL, N-SS, rest of OV)
-- Open-arc buffer, CompoundCurve hull, Fréchet, LEC
+- Full **OV** TAG — OV-P1 flipped; remaining named R2 are `H-SHELL-N-MIXED`, `H-SHELL-HOLE-CROSS`, `H-SHELL-HOLE-X`, `H-ANNULUS-TANGENT`. Circular noder + arrangement is OV-P2 / Bar 2 (different epic).
+- Public arc-arc / arc-line utilities and arc `SegmentString` (N-AA, N-AL, N-SS)
+- Open-arc buffer, CompoundCurve hull
+- Public `DiscreteHausdorffDistance` (D-HF) — still sees chords in general; TestBuilder laser only. `DiscreteHausdorffDistance` on #7 has closed-form for two pairs only: single-arc `CircularString` → single-segment `LineString` (apex √949/6 − 7/6 ≈ 3.967641), and two circular discs. A single-member `MultiSurface` of one disc is the same pair, not a third. D-HF honesty lives on draft [#45](https://github.com/grootstebozewolf/jts/pull/45).
+- Full LEC TAG (typed obstacle distance landed; public TAG is wider)
 - OFF = concentric arc (refactor)
 - RocqRefRunner SQL/MM suite for public Curve predicates
 - TestBuilder inspector `ClassCastException` (visual QA)
@@ -91,7 +98,7 @@ These closed-form subsets of **OV** and **R-PR** did **not** wait for N-SS. Line
 | `spec:` | This epic + 49-method `CurveAwarenessSpecTest` red-test suite |
 | (orig)  | `bufferCurveWithParams` linearisation hook (Phase-5 spike entry) |
 
-#7 carried the SFA/SQL-MM types, WKT, and structural-type work forward from that spike. #8 stacked the PERF-GATE and the lasers above.
+#7 carried the SFA/SQL-MM types, WKT, and structural-type work forward from that spike. #8 stacked the PERF-GATE and the first lasers, then merged into #7. #10 and #11 merged on top. Drafts #12 and #13 remain stacked.
 
 ## 5. Tracking model
 
@@ -102,12 +109,12 @@ We are **not** opening 49 separate issues. Fragmenting the project board, spammi
 - Path: `modules/curve/src/test/java/org/locationtech/jts/spec/curveawareness/CurveAwarenessSpecTest.java`
 - Run: `mvn -pl modules/curve test -Dtest=CurveAwarenessSpecTest`
 - Still has **all 49 `fail()` methods**. That “delete the method when a TAG ships” meter **froze** when work moved to stacked PRs and closed-form lasers.
-- The class is the **full-TAG red list**, excluded from default Surefire. It is **not** the live scoreboard. Do **not** delete a method because a closed-form subset landed (OV Phase 0, R-PR disc cells, disc area, TestBuilder Hausdorff, …). Delete only when the *full* TAG ships.
+- The class is the **full-TAG red list**, excluded from default Surefire. It is **not** the live scoreboard. Do **not** delete a method because a closed-form subset landed (OV-P1 kits, R-PR disc cells, disc area, TestBuilder Hausdorff, …). Delete only when the *full* TAG ships.
 - Local silence while working: `mvn -Dtest='!CurveAwarenessSpecTest' test`.
 
 ### Live progress meter
 
-Remaining **full** TAGs (still red in the spec class) plus the **green tests next to production code on #8** (and the Notion board). A maintainer reading this epic should look at OverlayNGCurve / `CurveExact` / WKB tests on #8, not at “49 methods remaining”.
+Remaining **full** TAGs (still red in the spec class) plus the **green tests next to production code on #7** and the Notion board [JTS curve laser — progress](https://www.notion.so/JTS-curve-laser-progress-3bd1c9833b068135bd74e817b67e77eb). A maintainer reading this epic should look at OverlayNGCurve / `CurveExact` / WKB tests on #7 and that page, not at “49 methods remaining”.
 
 ### GitHub layout
 
@@ -137,11 +144,13 @@ Most TAGs ship purely inside `jts-curve` (extension module, opt-in). A handful r
 
 | TAG group | jts-core change? | Notes |
 |---|---|---|
-| **WKB 8–12** | **Yes (landed on #8)** | `WKBReader` switch, `WKBConstants` 8–12, `GeometryFactory` `create*` stubs (default throw). `CurveGeometryFactory` / `CurveWKBWriter` / `CurveWKBReader` stay in `jts-curve`. |
+| **WKB 8–12** | **Yes (on #7; landed via #8)** | `WKBReader` switch, `WKBConstants` 8–12, `GeometryFactory` `create*` stubs (default throw). `CurveGeometryFactory` / `CurveWKBWriter` / `CurveWKBReader` stay in `jts-curve`. |
 | **F-RD** | Possibly | Only if `ShapeWriter` needs new extension hooks for `CurvePolygon` rings. |
-| **N-AA, N-AL, N-SS** | **Yes** | `SegmentString` / `Noder` hierarchy lives in core. **Largest remaining core surface** in the epic. |
-| **OV** | Indirect | *General* overlay still depends on N-SS; the pipeline itself stays in core. Closed-form subsets (OverlayNGCurve Phase 0, R1.5 / R1.6) shipped in `jts-curve` without a public noder. |
+| **N-AA, N-AL, N-SS** | **Yes** | `SegmentString` / `Noder` hierarchy lives in core. **Largest remaining core surface** in the epic. OV-P2 / Bar 2 — different epic; do not start from this PR. |
+| **OV** | Indirect | *General* overlay still depends on N-SS; the pipeline itself stays in core. Closed-form kits (OverlayNGCurve R0–R1.7, R-LL, R-AA, nested annulus) shipped in `jts-curve` without a public noder. OV-P1 flipped. |
 | **R-PR, R-CONT** | Indirect | `RelateOp` lives in core. Disc cells shipped via `CurveExact` in `jts-curve`. General “any curved/flat pair” still wants N-SS. |
+| **D-HF** | Two pairs only | Public `DiscreteHausdorffDistance` still sees chords in general. `DiscreteHausdorffDistance` on #7 has closed-form for two pairs only: single-arc `CircularString` → single-segment `LineString` (apex √949/6 − 7/6 ≈ 3.967641), and two circular discs. A single-member `MultiSurface` of one disc is the same pair, not a third. Exact path skips densify; densify 0.05 is not the laser. Honesty: draft [#45](https://github.com/grootstebozewolf/jts/pull/45). |
+| **LEC** | Yes (partial) | Typed obstacle distance (point / segment / polygon / arc / disc) and certified disc closed form. Public TAG is wider. |
 | **PLG** | **Yes** | `Polygonizer` lives in core; needs to accept `CompoundCurve` edges. |
 | **PRC-SN** | Yes | `PrecisionModel.makePrecise` integration. |
 | **DSF** | Yes (or shadow) | `Densifier` lives in core; alternative is to wrap and shadow it from `jts-curve`. |
@@ -153,7 +162,7 @@ Everything else is jts-curve-only or `jts-app` (TestBuilder).
 - **Backwards compatibility on structural composites.** Algorithms that don't recognise a curve subtype today silently densify. After **F-CP**, a third-party algorithm that doesn't know about the new structural CurvePolygon ring will see a `CompoundCurve` shell where it expected a `LinearRing`, and may throw. We need a fallback contract: the structural ring must implement enough of `LinearRing`'s contract to keep old code limping (read-only chord coords still available), *or* the structural CurvePolygon must fail fast with a clear message instead of silently going wrong.
 - **`equalsExact` semantic change** (R-EQ). Today `CIRCULARSTRING(p0,p1,p2).equalsExact(LINESTRING(p0,p1,p2))` returns true via shared coordinates. Making it false is per spec, but it's a behaviour change for any user comparing-by-WKT-text. Needs a release note. Still open.
 - **Non-similarity affine** (AT-NS). Sheared arcs are ellipse arcs, which JTS doesn't model. The plan is to detect-and-densify, but: what does `getGeometryType()` return on the result? If `LineString`, we've changed the type silently. If still flagged as `CircularString`, the polyline lies about its identity. Decide before AT-NS lands.
-- **Performance of public arc-arc / arc-line intersection** (N-AA, N-AL). The two-circle solve is fine for low cardinality, but `MCIndexNoder`-equivalent indexing of arc spans (bounding-box pruning of arcs) is non-trivial. Worth a benchmark before committing to a design. R1.6 uses line–circle clip internally; that is not the public utility.
+- **Performance of public arc-arc / arc-line intersection** (N-AA, N-AL). The two-circle solve is fine for low cardinality, but `MCIndexNoder`-equivalent indexing of arc spans (bounding-box pruning of arcs) is non-trivial. Worth a benchmark before committing to a design. R1.6 uses line–circle clip internally; R-LL / R-AA are overlay kits. None of those is the public utility. Do not start a circular noder from this PR.
 - **Z / M propagation across densified arcs.** Out of scope for behaviour changes here, but every TAG that produces densified output (DSF, AT-NS, …) should choose a Z/M policy that doesn't lock us out of a proper interpolation later.
 
 ## 8. Definition of Done (epic-level)
@@ -162,16 +171,18 @@ The epic closes when **all** of:
 
 1. `CurveAwarenessSpecTest` is empty — every TAG's red test deleted, replaced by green tests next to its production code.
 2. The 6 curve types round-trip through every public `Geometry` operation in the user guide without producing flat output where curve-preserving output is mathematically possible.
-3. **WKB curve types** — satisfied on #8. ISO/OGC codes 8–12 read through core `WKBReader` + a curve-capable factory; `CurveWKBWriter` emits them. The Draft v3 “open a WKB sibling issue” action is done by that work, not by a separate issue. (3-D / ELLIPSARC / Z-M interpolation remain deferred as in §3.)
+3. **WKB curve types** — satisfied on #7 (landed via #8). ISO/OGC codes 8–12 read through core `WKBReader` + a curve-capable factory; `CurveWKBWriter` emits them. The Draft v3 “open a WKB sibling issue” action is done by that work, not by a separate issue. (3-D / ELLIPSARC / Z-M interpolation remain deferred as in §3.)
 4. A release note covers the `equalsExact` change (see §7) and any other user-visible behaviour shifts.
 
 **TB-FN (function-tree curve-awareness badges) is a stretch goal**, not a DoD criterion. Annotating every entry in TestBuilder's function tree is a multi-week task with low payoff relative to the algorithm work, and shouldn't gate epic closure.
 
+**OV-P1 is not epic DoD.** The full OV TAG stays red until a general circular noder and arrangement exist; that is OV-P2 / Bar 2, a different epic.
+
 ## 9. Phases — work breakdown
 
 Phases group TAGs that share dependencies or naturally land together. Within a phase, TAGs are usually independently shippable. Cross-phase dependencies are noted explicitly per phase.
 
-**Closed-form subsets of Phase 6 (and pieces of Phases 2–4) already landed on #8 without Phase 5.** That does not turn those TAGs green. Annotate **partial** and name the subset. General overlay / polygonizer / coverage / `equalsExact` still wait on Phase 5.
+**Closed-form subsets of Phase 6 (and pieces of Phases 2–4) already landed on #7 without Phase 5.** That does not turn those TAGs green. Annotate **partial** and name the subset. General overlay / polygonizer / coverage / `equalsExact` still wait on Phase 5. OV-P1 flipped; remaining named R2 are listed in §4.1.
 
 ### Phase 1 — Foundations (jts-curve structural completeness)
 
@@ -199,7 +210,7 @@ Mirror the `CompoundCurve` work onto the remaining composite types.
 
 - **D-PT / D-AA** — analytical point-arc and arc-arc distance. Closed-form helpers exist in `CurveExact`; the public `DistanceOp` TAG is still red.
 - **D-OP** — `DistanceOp` accepts curved inputs without forced densification. Still the public TAG; keep the spec method.
-- **D-HF** — `DiscreteHausdorffDistance` / `DiscreteFrechetDistance` parameterise by arc length. **Partial (half-red):** TestBuilder `CurveExactFns` laser only. Public `DiscreteHausdorffDistance` still sees chords. Keep the spec method. Fréchet is still open.
+- **D-HF** — **Partial (half-red):** public DHD still sees chords in general; TestBuilder `CurveExactFns` laser only. `DiscreteHausdorffDistance` on #7 has closed-form for two pairs only: single-arc `CircularString` → single-segment `LineString` (apex √949/6 − 7/6 ≈ 3.967641), and two circular discs. A single-member `MultiSurface` of one disc is the same pair, not a third. Exact path skips densify; densify 0.05 is not the laser. Keep the spec `fail()`. D-HF honesty lives on draft [#45](https://github.com/grootstebozewolf/jts/pull/45).
 - **C-LIN / C-AREA / C-IP** — centroids and interior point.
 
 **Depends on:** Phase 1 (F-CP for `CurvePolygon` cases).
@@ -219,14 +230,14 @@ Mirror the `CompoundCurve` work onto the remaining composite types.
 ### Phase 5 — Noding foundation
 
 - **N-AA** — public arc-arc intersection utility. **Still red.**
-- **N-AL** — public arc-line intersection utility. **Still red.** Line–circle clip is used inside R1.6; that is not this TAG.
-- **N-SS** — arc-aware `SegmentString` / `NodedSegmentString` and integration with the `Noder` hierarchy. **Still red.**
+- **N-AL** — public arc-line intersection utility. **Still red.** Line–circle clip is used inside R1.6; R-LL / R-AA are overlay kits; those are not this TAG.
+- **N-SS** — arc-aware `SegmentString` / `NodedSegmentString` and integration with the `Noder` hierarchy. **Still red.** OV-P2 / Bar 2 — different epic; do not start from this PR.
 
 **Depends on:** Phase 1. **Touches `jts-core`** — see §6. Phase 6 *general* overlay still depends on N-SS.
 
 ### Phase 6 — Overlay, Predicates, Polygonizer, Coverage
 
-- **OV** — arc-preserving overlay output (`union` / `intersection` / `difference` / `symDifference`). **Partial (closed-form subset):** OverlayNGCurve Phase 0 — R0 / R1 / R1.5 two-disc / R1.6 disc vs hole-free plain polygon; reverse dispatch; Multi unwrap. **Not** a general circular noder. CompoundCurve overlay still open. Do not mark OV green.
+- **OV** — arc-preserving overlay output (`union` / `intersection` / `difference` / `symDifference`). **Partial (closed-form subset):** OverlayNGCurve R0 / R1 / R1.5 two-disc / R1.6 disc vs hole-free plain polygon / R1.7 CompoundCurve-shell kits (two-node, two-shell, collinear, 0/1-node, even-n, tangent-odd NSpan, same-outer hole, different-outer punch) / R-LL / R-AA / D4 nested annulus (`16π`, covers `EEEE` / coveredBy `EE0E`). **OV-P1 flipped.** Remaining named R2: `H-SHELL-N-MIXED`, `H-SHELL-HOLE-CROSS`, `H-SHELL-HOLE-X`, `H-ANNULUS-TANGENT`. **Not** a general circular noder. Circular noder + arrangement is OV-P2 / Bar 2 — different epic; do not start. Do not mark the *full* OV TAG green.
 - **R-PR / R-CONT / R-EQ** — arc-aware relate, predicates, exact equality. **R-PR / R-CONT partial:** certified disc PIP; DE-9IM for disc vs Point / LineString / hole-free Polygon / second disc; MultiSurface unwrap; SFS table; two areas never `crosses`. Half-disc / CompoundCurve still null → linearise. **R-EQ** (arc-vs-chord `equalsExact`) still open.
 - **PLG** — `Polygonizer` accepts `CompoundCurve` edges and emits `CurvePolygon` faces.
 - **COV** — `CoverageUnion` preserves shared arc edges.
@@ -246,7 +257,7 @@ Three single-theme tracks that depend only on Phase 1 and have no inter-dependen
   - **TB-FN** — function-tree curve-awareness badges (●/◯/✕). *Stretch goal* — see §8.
   - Visual QA still open: TestBuilder inspector `ClassCastException`.
 
-Most of Phase 2 / 4 / 7 TAGs are still the full red list. Also still open (not a phase of their own): RocqRefRunner SQL/MM suite for public Curve predicates; LargestEmptyCircle (LEC).
+Most of Phase 2 / 4 / 7 TAGs are still the full red list. Also still open (not a phase of their own): RocqRefRunner SQL/MM suite for public Curve predicates. **LEC** is partial (typed obstacle distance for point / segment / polygon / arc / disc); the public TAG is wider.
 
 ## 10. Suggested order
 
@@ -255,16 +266,20 @@ Phase 1 (Foundations)
    │
    ├──> Phase 2 (Properties)            M-AREA-CP partial: circular discs
    ├──> Phase 3 (Measurement)           CurveExact helpers; D-HF half-red
+                                        (public DHD still sees chords; Fréchet open)
    ├──> Phase 4 (Construction)          H-CV partial: disc / arc hulls
    ├──> Phase 5 (Noding)  ──>  Phase 6 *general* OV / PLG / COV / R-EQ
+   │                            (OV-P2 / Bar 2 — different epic)
    │
-   └──> Phase 6 *subsets* (already on #8, did not wait for N-SS)
-            OverlayNGCurve Phase 0 (R0 / R1 / R1.5 / R1.6)
+   └──> Phase 6 *subsets* (already on #7, did not wait for N-SS)
+            OverlayNGCurve R0 / R1 / R1.5 / R1.6 / R1.7 + R-LL / R-AA
+            D4 nested annulus; OV-P1 flipped
+            remaining named R2: MIXED / HOLE-CROSS / HOLE-X / H-ANNULUS-TANGENT
             R-PR / R-CONT closed-form disc cells
    └──> Phase 7 (Independent tracks: snap / triangulation / TestBuilder)
 ```
 
-After Phase 1 finishes, Phases 2 / 3 / 4 / 5 / 7 can run in parallel. **Phase 6 general overlay still waits for Phase 5.** Phase 6 *subsets* (two-disc overlay, disc-vs-polygon overlay, disc DE-9IM) already shipped on #8 without a public noder. The phase graph must not say “overlay requires a noder” as if those subsets were blocked.
+After Phase 1 finishes, Phases 2 / 3 / 4 / 5 / 7 can run in parallel. **Phase 6 general overlay still waits for Phase 5.** Phase 6 *subsets* (two-disc overlay, disc-vs-polygon overlay, CompoundCurve-shell kits, lineal R-LL / R-AA, nested annulus, disc DE-9IM) already shipped on #7 without a public noder. The phase graph must not say “overlay requires a noder” as if those subsets were blocked.
 
 ## 11. Conventions
 
@@ -289,10 +304,15 @@ After Phase 1 finishes, Phases 2 / 3 / 4 / 5 / 7 can run in parallel. **Phase 6
 
 - OGC Simple Feature Access 1.2.1 / ISO 19125-2.
 - `jts-curve` source: `modules/curve/`.
-- [#7](https://github.com/grootstebozewolf/jts/pull/7) `feature/sfa-curve-rgr` — SFA/SQL-MM types, WKT, structural types.
-- [#8](https://github.com/grootstebozewolf/jts/pull/8) `cursor/curve-perf-gate-45a0` — PERF-GATE, OverlayNGCurve, `CurveExact`, WKB 8–12. Tip of this retip: `488c48ba`.
+- Parent epic: [locationtech/jts#1195](https://github.com/locationtech/jts/issues/1195).
+- [#7](https://github.com/grootstebozewolf/jts/pull/7) `feature/sfa-curve-rgr` — live tip `210f1b16` (merge of #11). SFA/SQL-MM types, WKT, structural types, PERF-GATE, OverlayNGCurve kits, `CurveExact`, WKB 8–12.
+- [#8](https://github.com/grootstebozewolf/jts/pull/8) `cursor/curve-perf-gate-45a0` — **merged into #7**. PERF-GATE and the first closed-form lasers, including WKB 8–12.
+- [#10](https://github.com/grootstebozewolf/jts/pull/10) nested annulus (`92fdbb71`) — **merged into #7**.
+- [#11](https://github.com/grootstebozewolf/jts/pull/11) odd-n tangent NSpan (`d8c5824f`) — **merged into #7**.
+- Draft [#12](https://github.com/grootstebozewolf/jts/pull/12) (`3cc5f1a5`) — stamps `H-SHELL-HOLE-CROSS` + `H-SHELL-HOLE-X`. Stacked, not merged.
+- Draft [#13](https://github.com/grootstebozewolf/jts/pull/13) (`73703036`) — stamps `H-ANNULUS-TANGENT`. Stacked, not merged.
 - OverlayNGCurve (package-private overlay helpers in `org.locationtech.jts.operation.overlayng.curve`).
 - `CurveExact` (package-private in `org.locationtech.jts.geom.curve`).
 - GEOS `src/io/WKBReader.cpp` / `WKBWriter.cpp` / `include/geos/io/WKBConstants.h` — type codes 8–12 and child-WKB layout.
 - Spike branch (origin): `feature/sfa-curve-buffer-spike` on `grootstebozewolf/jts`.
-- `CurveAwarenessSpecTest` — full-TAG red list (49 `fail()` methods still present; excluded from default Surefire). Live meter: #8 green tests + remaining full TAGs.
+- `CurveAwarenessSpecTest` — full-TAG red list (49 `fail()` methods still present; excluded from default Surefire). Live meter: #7 green tests + [JTS curve laser — progress](https://www.notion.so/JTS-curve-laser-progress-3bd1c9833b068135bd74e817b67e77eb).