Recommended Resolution: 1440p (Though I think you can get away with 720p as well because lol 3DS)
So, I've learned how to create overlays for univrsal's Input Overlay plugin for OBS and decided to cook up a 3DS-related overlay. It's meant for 2160p (4K), but because it's for OBS, you can just scale it down to whatever you like anyway.
Input Overlay (Github):
https://github.com/univrsal/input-overlay3DS Overlay: I'd say check back tomorrow, to be honest.
...
https://www.youtube.com/watch?v=7XHyvNNaO4I