Cutout for the wireless receiver PCB adjusted. The newer (probably cheaper) models shipping from Amazon have a square PCB instead of the 45 corners like the picture in the description. This will fit both variants and worst case have to use some double sided tape to hold it down.
Removed side notch for external wiring
Adjusted the “L” cutout on the bottom. I'm not sure if Bambu changed the bottom plastic of the enclosure but I had to lengthen the cutout by a few mm each way to get the receiver box to “click” into place and sit flat.

Upper Receiver Box Changes

Added wiring channel down center to run fan wiring
Removed notches for external wiring
Removed cutouts for buck/boost converter
Note 1: I ran 5V fans to simplify things so no converter is needed
Note 2: You will also need to add a small hole to the fan case that sits above to run the wiring. Either in CAD or just do what I did (wasn't going to reprint the part) and drill a small hole.

Fan Shim

I ran into issues installing where 20mm m3 screws were too short and 25mm m3 screws would bottom out. This 2mm shim slides down into the fan box between the box and fans and allows for 25mm to be used. Maybe someone can print this out of TPU to see if it does anything for noise/vibration reduction?

Updated (Feb 2024) "Clean wiring" Receiver

Summary