I'm no stranger to upgrading firmware, but I'm going to have print out bushings to move the motor mounts further out from the frame as well to so the shaft and coupler will clear the Y axis bar its so tight now i can't even put a zip tie on it without the rod spinning the plastic sleeve and hitting the bar. For now I'll just order the M5 shaft & coupler and use the existing threaded rods, I'll just have to make a modified the Z-nut trap to accommodate for the offsetting of the motors.

Thanks, is there a resource you used to do your upgrade (ie like a guide with a kink to the required firmware? I would like to do it in the future.