[Feature Request][Wii U]For Sameboy core when emulating 2 Game Boys at once, a screen layout option where one Gameboy is on the TV and the other Gameboy is on the Wii U Gamepad

So this isn't a bug, it's just a simple enough feature request I'd think. As the title reads, would it be possible to add a screen layout option for Sameboy link cable emulation, where one GameBoy is on the TV, and the other GameBoy displays on the Wii U Gamepad's screen? We already have an option to display them in 2 orientations, next to each other or on top of each other. I'd think that the 2 screens can function independently of each other in retroarch in the Wii U if the programming is there, but it does seem to strictly mirror each other at the moment. I apologize if this isn't the right place to request such a feature, but it would be really cool to have happen if possible.

Start by tracing RetroArch's Wii U display and screen-layout handling alongside the SameBoy link-cable emulation path. Confirm how the two screens are currently mirrored and whether the TV and GamePad can receive separate outputs; done means a selectable layout supports one Game Boy on each display during two-Game-Boy emulation.