Here is a rebuild in Fusion 360 for the D6 Bondtech Mount. I added the cad files With history to aid with more modifications.
This was built off the original STL Which had some issues and ATM I am unable to verify the exact hole sizes (but this does match the STL)
PLEASE post verified dimensions or just take these files and update them :)
Update, I made some modifications to the initial design which was a cad copy for development. This should be stable and able to use the stock screws.
The new files break this up into 3 parts, That should be snap together (though I would glue it also)
Note the Upper frame needs to be printed on its side. Big hole facing the build plate. (this allows best orientation strength).
Update. A reference shifted and moved items out of alignment in V3 if you downloaded it, delete it and download v4.
Update. V4 works well so far
Depending on your printing you may need to ream out the base/guide holes. The entire part snaps together better then I expected and when assembled with motor is quite rigid and does not require glue (though you can always use it). The original machine screws with the Botbit BMG extruder now work (previous versions and other versions they were too short)
additional work Maybe making the guide a bit shorter. And make a custom wiring/connector holder.
Update added Cable cover and ribbon cable stress relief. Not the final version but works. Currently glue together, making a snap together version