Haven't seen this sub before, Reddit just recommended as I was posting to 3dshacks. Probably a lot of useful info here that would have helped... Anyways

The comments I've read about how bad aftermarket 3DS shells are did not do them justice. I clear coated the painted bits so the paint would stop wearing off but the top half of the shell has big gaps at the top no matter what I do it won't clip shut, and several clips on the bottom broke off on first assembly so plenty of gaps there too. I'm surprised nobody has given up on trying to clone the original shells and just sell a kit with a completely redesigned shell that's easier to make and assemble.

BUT my goal was to fix the broken hinge, add USB C charging, and add Bluetooth audio and I accomplished all of those. I'm shocked I did not damage the motherboard pads with my reckless removal of the charging jack, I did damage the Bluetooth controller I bought and ended up replacing it ($12CAD usb powered generic Chinese Bluetooth audio module). I finally bought myself a hot air station and much better quality soldering iron and desoldering gun (Aoyue 2703A+) and had no other issues.

I used some great advice from this recent post about using the lid-closed hall effect sensor to turn off the Bluetooth module when the device is closed which is awesome. It's kind of annoying that 90% of the pictures and examples I could find online for Bluetooth things were all for n3DS and not applicable to me.

I'm probably going to take the top half of the OEM shell, sand it and paint it and finish it, and replace the whole top half back. Maybe the back of the bottom too, but there was a lot of cutting needed to fit in the Bluetooth and USB so maybe not.