I did not realize they were using M2.5 hardware originally. (downloaded  the file only to rediscover it later on) 

I enlarged the holes in the design to accommodate for the upsized hardware, and made them “acorn” shaped to avoid and undersized ID. In addition, I got rid of the radii on either end and opted for a chamfer to increase reliability when printing. I uploaded a STEP file for anyone else that wants to modify this Remix (say to use M2.5 heat-set-inserts) Sorry the STEP is probably kind of messy, Fusion did not want to generate me nice face groups on this model. 

Ruthex heat-set-inserts can be purchased on Amazon. 

Many thanks to @d0pefish for their work on the original design!