Add --center-window option to vertically center the modules based on their window, rather than the default of centering based on flap/letter centers
Improve export performance drastically by omitting the 3d splitflap modules entire in projection rendering mode
Fix --center-center-x and --center-center-y arguments
Change dog bone shape (and front face M4 hole) to rectangles to simplify the 2d geometry that's exported for external CAM (Fusion 360 did not perform well with all of the polygon-ized cricles)
--center-windowoption to vertically center the modules based on their window, rather than the default of centering based on flap/letter centers--center-center-xand--center-center-yarguments