Make a clamshell Switch with an extra screen and a DS/3DS cart port (and an ARM11 processor inside). Bridge the two systems like the original DS/lite did (it had a GBA port on the bottom and an ARM7 co-processor).
Would also protect the screens in transit, which tbh is my biggest reservation about a Switch (and it’s a bit big to carry). Call it a 3wiDtchS, idc take my money