Ender-3 V2 adjustable Z-Stop - improved

This is my attempt to improve the upper moving part of this design: https://www.thingiverse.com/thing:4845526. Two changes:

1. __Reverse installation of the Z-stop switch is now possible__ (some people prefer it this way for more precision and consistency). I made the recess for the soldered pins on the other side of the mounting plate and adjusted its shape for clearance. So, just mount the PCB with the switch on either side of the plate.
2. __Additional guide bracket__. I found that the part was not holding in the slot very well, so this bracket "hugs" the corner of the 2040 frame post and catches the slot on the front side of the post.

The fit would depend on the dimensional accuracy of your printer and your slicer settings. Some minor filing (but not much) may be needed to get a smooth movement with minimal play. It does take a bit of force to snap the part into place - don't be afraid to break it (I couldn't, although I tried, LOL). To remove the part, just use a flat-blade scre