This is a MOSFET board mount for my Monoprice Maker Select v2.1. It's similar to the one linked as a remix, but it was created from the ground up. The main feature is the standoff holes have threads for M3x6mm screws, which you should have a ton of if you've done the Z-brace mod.
I made the bottom solid so that you can use velcro or double-stick tape to adhere it to the inside of the case.
MOSFET Board is available here:
20% or solid, doesn't really matter
The M3 threads are pretty fine, so the smaller resolution/layer height you can print it at the better. I did mine at 0.12mm and the threads worked pretty well.