To answer a few of the questions:
I'm using Cherry MX Clears, stock switches that came with my Varmilo VA68Mg. They've never been opened, desoldered, etc. This is the first time I've pulled the caps from the board to swap them out, and I've confirmed that it's definitely that deformity that's causing the key to catch a bit when I release it. The stock caps are fine, as are the ones without the deformity. My guess is I tend to push a little bit south when I type (the deformed wall is at the bottom of the caps -not the right side- I just forgot to rotate the picture), so the keycap pushes down a little and catches.
I've got an email out to Originative, but this is my first experience with GMK so I wasn't sure if this was a known issue or something. If it were just a couple keys I'd just clean them up with a dremel and move on, but I have about two complete rows plus my accents which are like this.