SubD is a Ruby C-extension. Cracks that modify the license check often break its API hooks. That means:
Build that instead.
Trimble bundles SubD within the subscription (currently $699/year for professional use). Studio includes: sketchup subd license key hot
Architects use it for parametric facades. Furniture designers use it for molded plywood. Product designers use it for ergonomic handles. It fills a gap that SketchUp itself has ignored for 20+ years. SubD is a Ruby C-extension