I'm surprised there isn't a 3DS mod to bodge in a fancy modern panel with enough DPI to hit the lowest common multiple of those screens' resolutions, such that

I'm surprised there isn't a 3DS mod to bodge in a fancy modern panel with enough DPI to hit the lowest common multiple of those screens' resolutions, such that it can pull off a full-coverage integer-scaled mode for both DS and 3DS games. (There certainly exist enough mods that do this for GB/GBC!)