Giving the ability to display the SNES output on the bottom screen would be pretty interesting and useful: for 2|3DS devices with a broken top screen, for GB Macro builds, and for using the touchscreen as a mouse in Mario Paint (if the SNES Mouse gets implemented in that way).
There's also some people that doesn't like how the pixels on the top screen of 2|3DS devices look and the scanline it adds (except for the o2DS), so that's another use case for this feature.
Giving the ability to display the SNES output on the bottom screen would be pretty interesting and useful: for 2|3DS devices with a broken top screen, for GB Macro builds, and for using the touchscreen as a mouse in Mario Paint (if the SNES Mouse gets implemented in that way).
There's also some people that doesn't like how the pixels on the top screen of 2|3DS devices look and the scanline it adds (except for the o2DS), so that's another use case for this feature.