Update 8/15/2021: Some updates to the design. I'm testing some of the changes, but the MicroSD card will probably not be tested since that is a component from a previously verified design which was just spliced into this design.
Update 8/19/2021: The design is completed and tested, and now uploaded to Thingiverse. You can find it here:
https://www.thingiverse.com/thing:4936218