take a look at my other designs https://www.thingiverse.com/mg_evolution/designs
Eachine Wiazard X220 Rear LED mount.
This should be printed without supports and at 0.15 mm layer height. (I printed at 2.0 and it was fine)
The mount is not secured vertically. It uses the rear uprights to slide onto.
The LED is mounted in the slots on the print using 2x m3x10 screws, securing the LED frame.
The screw holes are 3.10 on tinkercad but have a flat roof to allow the screws to bite in. A bit of super glue can be used to prevent them coming loose but I have not had this problem.