I have designed frames for holding the Trill Bar and Square. They are a press fit and should serve as a time saving starting point for anyone intending to include the Bar or Square in a 3d design or print. This forms the start of a ergonomic synth print project for me. I will post the results when finished.
The STL files can be downloaded from the following pages.
Bela Trill Square Frame STL File
https://www.thingiverse.com/thing:4615619
Bela Trill Bar Frame STL File
https://www.thingiverse.com/thing:4615637