Here are 2 add ons that I made for my Millwright M3 CNC Mill. I was concerned about the cable management and of the cables falling into the toolpath or catching on the work along the X-axis. Also, I did not like the fan setup, so I created something that can cover the components better as well as give the fan more stability.

Creality

Ender 3

No

No

200

20

Supports are not needed to print, however, the case will come out cleaner if you wish to use them.
You will need two M5 30mm bolts along with 2 M5 V-Slot locking nuts for the cable clips.