I didn't have enough clearance to mount it without forcing it. Also, I would have preferred it to be compatible with my Philips Hue bulbs. Thanks to the file shared by Ernz, I was able to modify his diffuser to make it a universal diffuser, and therefore compatible with Philips Hue bulbs.

I suggest applying a small amount of glue between the base and the diffuser, and printing the diffuser with supports only on the lower part. I will modify the design further so that it can be printed without supports. Be careful when removing the tray; handle it gently! It's fragile!