Yeah, their quarter turn insert is terrible. I can't even use that side as I have a Wahoo, but I popped the old Edge 500 into it to test it out, and it made a startling crackle sound on both insertion and removal. Seems to be glued in as well, so one less level of trust.

I imagine it could be popped out and replaced with a proper nylon mount, but I'm happy with it in the "upside-down" configuration. It's lightweight, unobtrusive, and seems to work well enough as a be seen light. Battery life seems to at least match the mfr. claims.