It was at this point I got my engineer friend involved. He solved some issues on the backplate and really just went over everything again. He is much more proficient at CAD than I am, and as a bonus, is also a machinist.

I then moved to measuring all the accessories. Huge PITA. Used a surface plate and height mic, but allowed everything to get transferred into Solid Works:



It was coming together, but still not happy with belt wrap, so more tweaks were needed. Ended up adding 4 idlers and a mechanical tensioner to achieve proper belt wrap and length.
Also wanted to incorporate the crank sensor bracket.



Performed some lightening on the plate and then ran some FEA test.


Made a few modifications that affected weight very little but increased strength 35%.