IKEA Enclosure - Plexiglass Mid Section Bracket (multiple sizes) -- v2 (Updated 2018/07/28)

I wanted to stop the plexiglass from flexing in the mid section of the Original Prusa i3 MK3 Enclosure - Ikea Lack Table (https://www.thingiverse.com/thing:2864118). And found this great design https://www.thingiverse.com/thing:2974739.

However, I also wanted to make sure that it would be easy to slide the plexiglass back into the bottom mid brackets. Whenever the top part of the enclosure slides back into place with the bottom part. This is why I opened up the top part of the bracket to h