# Native review - September 20 / Version 28.7

## What improved
Direct Fusion difference checks identify four changed print bodies: rear shell, front shell Body1, LED housing and optical body A. The other nine print bodies have no positive-volume difference. Native static play-cap/front-shell and both PCB-laminate/shell overlaps from 28.6 are absent above 0.001 mm3. These are useful local improvements, not a motion or fully connected fit pass.

## Remaining work
Battery/rear-shell overlap is 40.761 mm3; play-base/nominal-switch is 10.800; front Body1/Body2 is 16.997; front/acoustic-film is 99.463. Rim/rear and rim/front overlaps remain 1549.969 and 2684.020 mm3, requiring material/compression intent. A new 0.114 mm3 rear-shell/resistor overlap means laminate clearance alone cannot establish complete board clearance. Plus/rear and minus/rear residuals are 0.0093 mm3 each; talk/rear is 0.0733 mm3. Numerous hardware/wire contacts remain classified in the complete intersection CSV.

## Exports and source health
The supplied rear STL is unchanged from September 19 despite the native rear-shell change. New native exports contain the current geometry. Approximately +5 mm Y raw-STL offsets remain for Plus, Minus, Talk and both optics. Original files are preserved separately.

Fusion has 221 timeline entries, with the same five warning entries: Sketch3 (77), Sketch9 (95), Sketch23 (181), Extrude23 (182), Sketch28 (184). Cached geometry opens; missing references still need repair and regeneration. Inventory contains 1775 bodies: 415 solids and 1360 non-solid PCB reference sheets. All 13 print bodies are solids. There are 414 visible solids; only All wiring:1 / Body1 remains hidden. The exported reference STEP reimports as 414 valid solids.

## Method and limits
Original geometry was not edited. Exact-solid Boolean operations use temporary native copies. All 78 print-body pairs and printed/reference pairs were screened by bounding boxes; 401 visible reference solids and all 402 reference solids were checked in separate passes. Both report 6 print/print and 33 print/reference overlaps, with no Boolean errors. Reporting threshold is 0.001 mm3. Copied bounds are compared with native proxy bounds. Native old/new difference checks use Fusion's own kernel; foreign-kernel difference results were not used as evidence.

This excludes full reference/reference checking, non-solid sheet collisions, motion, strength, process tolerances, tool access and physical performance. Intersection volume is not penetration depth or a machining offset. Default Fusion volume integration is approximate. Physical first-article tests remain unperformed.