BuildResult set PlateIndex to the stock index, so every sheet cut from the same stock shared one index; OpenNest.Api maps plates by it. Part geometry filtered only rapids, so scribe/etch moves counted as material - the bug OpenNest fixed in 1b5e1b1. Use SpecialLayers.IsMaterial. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>