What map-making feature would you like emulators to have?

[ReyVGM]

Like the title says, what features helpful to map-making you wish emulators would have?

I'm working with the author of SuperSNES9X (who has already added a ton of improvements over the regular snes9x) and I can push to get new stuff added to it.

So, what would your dream emulator be like for map-making? What helpful features would you like to have?

It could be tiny things obscure emulators already do, but more popular ones don't; or even features from external programs that could realistically be implemented in an emulator.

I think there's a tool that takes screenshots of games and auto stitches them together? It would be awesome if something like that could be implemented natively.