diff --git a/OpenNest.Engine.Qwen/QwenNestingEngine.cs b/OpenNest.Engine.Qwen/QwenNestingEngine.cs
index a3ed1b4..8b7bbe6 100644
--- a/OpenNest.Engine.Qwen/QwenNestingEngine.cs
+++ b/OpenNest.Engine.Qwen/QwenNestingEngine.cs
@@ -21,10 +21,10 @@ public sealed class QwenNestingEngine : INestingEngine
 
         // TODO: implement independent placement logic here.
         //
-        // Do NOT call NestingEngineRegistry.Create(...), PlateNesterFactory, or any
-        // FixedStrategyNestingEngine / StockLadderNestingEngine instance from inside this
-        // method. Decide placements yourself using OpenNest.Core / OpenNest.Geometry
-        // primitives (Polygon, NoFitPolygon, Collision, ConvexHull, RotatingCalipers, etc).
+        // Do NOT call NestingEngineRegistry.Create(...), PlateNesterFactory, PlateFillService,
+        // or any built-in INestingEngine, and do not run several and keep the best. The
+        // Fill/ and pattern components (FillLinear, PairFiller, PatternTiler, Compactor, ...)
+        // and OpenNest.Core geometry ARE fair game as tools; the decisions are yours.
         //
         // job.Parts        -> requested parts (PartGeometrySnapshot geometry, quantity, priority, rotation policy)
         // job.Plates        -> candidate stock sheets (size, spacing, quadrant, quantity)
diff --git a/OpenNest.Engine.Qwen/README.md b/OpenNest.Engine.Qwen/README.md
index c394df1..4a76745 100644
--- a/OpenNest.Engine.Qwen/README.md
+++ b/OpenNest.Engine.Qwen/README.md
@@ -1,24 +1,35 @@
 # OpenNest.Engine.Qwen
 
-An independent `INestingEngine` implementation — **not** a wrapper, ensemble, or
-selector over OpenNest's built-in engines (`StockLadderNestingEngine`,
-`FixedStrategyNestingEngine` "Default"/"Strip"/"Vertical Remnant"/"Horizontal Remnant`,
-or anything reachable through `PlateNesterFactory`/`NestingEngineRegistry`).
-`Solve()` must never call, instantiate, or otherwise delegate a placement decision
-to one of those.
+An independent `INestingEngine` implementation. It must not be a wrapper, ensemble, or
+selector over OpenNest's built-in engines. `Solve()` must not call, instantiate, or
+delegate to any existing `INestingEngine` (`StockLadderNestingEngine`,
+`FixedStrategyNestingEngine`), `NestingEngineRegistry`, `NestJobRunner`, or the whole-plate
+nesters/fillers behind `PlateNesterFactory` (`DefaultPlateNester`, `StripPlateNester`,
+`RemnantPlateNester`, `PlateFillService`, `DefaultPlateFiller`, ...). It must also never run
+several of them and keep the best result.
+
+The decisions that make it an engine must be yours: which sheet(s) to use, which parts go
+where and in what order, which pattern/strategy to apply to which region, and when to stop.
 
 ## Allowed building blocks
 
-Low-level geometry/data-structure primitives are fair game — they are not nesting
-strategies:
+Reuse is encouraged. These are tools you drive, composed by your own decision logic:
 
-- `OpenNest.Core` geometry: `Polygon`, `Shape`, `BoundingBox`, `Vector`, `Box`,
-  `ConvexHull`, `ConvexDecomposition`, `RotatingCalipers`, `Collision` (overlap/spacing
-  checks), `NoFitPolygon`, `ShapeProfile`, `SpatialQuery`.
-- `OpenNest.Engine` support types if useful: `PartBoundary`, `RotationAnalysis`,
-  `AngleCandidateBuilder` — the *decision logic* using them must be your own (don't just
-  call `BestFitFinder`/`PairEvaluator`/`RotationSlideStrategy`, which are the existing
-  best-fit engine's internals).
+- `OpenNest.Core` geometry: `Polygon`, `Shape`, `BoundingBox`, `Vector`, `Box`, `ConvexHull`,
+  `ConvexDecomposition`, `RotatingCalipers`, `Collision`, `NoFitPolygon`, `ShapeProfile`,
+  `SpatialQuery`.
+- Fill and pattern components in `OpenNest.Engine.Fill`: `FillLinear`, `FillExtents`,
+  `PairFiller`, `ShrinkFiller`, `RemnantFiller`/`RemnantFinder`, `Compactor`, `FillScore`,
+  `Pattern`/`PatternTiler`, `PartBoundary`, `RotationAnalysis`, `AngleCandidateBuilder`,
+  `BestCombination`.
+- `OpenNest.Engine.BestFit` (`BestFitFinder`, `PairEvaluator`, ...), `RectanglePacking`,
+  `CirclePacking`.
+
+If you find a faster or better way to do something a shared component already does (for
+example linear patterning), implement it inside this engine's own project and leave the
+shared code untouched. Do not edit `OpenNest.Core` or `OpenNest.Engine`. Call it out in your
+report (what it replaces, why it is better, measured numbers) so it can be generalized and
+upstreamed for every engine later.
 
 ## What to fill in
 
diff --git a/OpenNest.Engine.Terra/README.md b/OpenNest.Engine.Terra/README.md
index 2911596..74657ed 100644
--- a/OpenNest.Engine.Terra/README.md
+++ b/OpenNest.Engine.Terra/README.md
@@ -1,24 +1,35 @@
 # OpenNest.Engine.Terra
 
-An independent `INestingEngine` implementation — **not** a wrapper, ensemble, or
-selector over OpenNest's built-in engines (`StockLadderNestingEngine`,
-`FixedStrategyNestingEngine` "Default"/"Strip"/"Vertical Remnant"/"Horizontal Remnant`,
-or anything reachable through `PlateNesterFactory`/`NestingEngineRegistry`).
-`Solve()` must never call, instantiate, or otherwise delegate a placement decision
-to one of those.
+An independent `INestingEngine` implementation. It must not be a wrapper, ensemble, or
+selector over OpenNest's built-in engines. `Solve()` must not call, instantiate, or
+delegate to any existing `INestingEngine` (`StockLadderNestingEngine`,
+`FixedStrategyNestingEngine`), `NestingEngineRegistry`, `NestJobRunner`, or the whole-plate
+nesters/fillers behind `PlateNesterFactory` (`DefaultPlateNester`, `StripPlateNester`,
+`RemnantPlateNester`, `PlateFillService`, `DefaultPlateFiller`, ...). It must also never run
+several of them and keep the best result.
+
+The decisions that make it an engine must be yours: which sheet(s) to use, which parts go
+where and in what order, which pattern/strategy to apply to which region, and when to stop.
 
 ## Allowed building blocks
 
-Low-level geometry/data-structure primitives are fair game — they are not nesting
-strategies:
+Reuse is encouraged. These are tools you drive, composed by your own decision logic:
 
-- `OpenNest.Core` geometry: `Polygon`, `Shape`, `BoundingBox`, `Vector`, `Box`,
-  `ConvexHull`, `ConvexDecomposition`, `RotatingCalipers`, `Collision` (overlap/spacing
-  checks), `NoFitPolygon`, `ShapeProfile`, `SpatialQuery`.
-- `OpenNest.Engine` support types if useful: `PartBoundary`, `RotationAnalysis`,
-  `AngleCandidateBuilder` — the *decision logic* using them must be your own (don't just
-  call `BestFitFinder`/`PairEvaluator`/`RotationSlideStrategy`, which are the existing
-  best-fit engine's internals).
+- `OpenNest.Core` geometry: `Polygon`, `Shape`, `BoundingBox`, `Vector`, `Box`, `ConvexHull`,
+  `ConvexDecomposition`, `RotatingCalipers`, `Collision`, `NoFitPolygon`, `ShapeProfile`,
+  `SpatialQuery`.
+- Fill and pattern components in `OpenNest.Engine.Fill`: `FillLinear`, `FillExtents`,
+  `PairFiller`, `ShrinkFiller`, `RemnantFiller`/`RemnantFinder`, `Compactor`, `FillScore`,
+  `Pattern`/`PatternTiler`, `PartBoundary`, `RotationAnalysis`, `AngleCandidateBuilder`,
+  `BestCombination`.
+- `OpenNest.Engine.BestFit` (`BestFitFinder`, `PairEvaluator`, ...), `RectanglePacking`,
+  `CirclePacking`.
+
+If you find a faster or better way to do something a shared component already does (for
+example linear patterning), implement it inside this engine's own project and leave the
+shared code untouched. Do not edit `OpenNest.Core` or `OpenNest.Engine`. Call it out in your
+report (what it replaces, why it is better, measured numbers) so it can be generalized and
+upstreamed for every engine later.
 
 ## What to fill in
 
diff --git a/OpenNest.Engine.Terra/TerraNestingEngine.cs b/OpenNest.Engine.Terra/TerraNestingEngine.cs
index 897f3e1..9b1bfa9 100644
--- a/OpenNest.Engine.Terra/TerraNestingEngine.cs
+++ b/OpenNest.Engine.Terra/TerraNestingEngine.cs
@@ -21,10 +21,10 @@ public sealed class TerraNestingEngine : INestingEngine
 
         // TODO: implement independent placement logic here.
         //
-        // Do NOT call NestingEngineRegistry.Create(...), PlateNesterFactory, or any
-        // FixedStrategyNestingEngine / StockLadderNestingEngine instance from inside this
-        // method. Decide placements yourself using OpenNest.Core / OpenNest.Geometry
-        // primitives (Polygon, NoFitPolygon, Collision, ConvexHull, RotatingCalipers, etc).
+        // Do NOT call NestingEngineRegistry.Create(...), PlateNesterFactory, PlateFillService,
+        // or any built-in INestingEngine, and do not run several and keep the best. The
+        // Fill/ and pattern components (FillLinear, PairFiller, PatternTiler, Compactor, ...)
+        // and OpenNest.Core geometry ARE fair game as tools; the decisions are yours.
         //
         // job.Parts        -> requested parts (PartGeometrySnapshot geometry, quantity, priority, rotation policy)
         // job.Plates        -> candidate stock sheets (size, spacing, quadrant, quantity)