What works depends on what your trying to emulate. A few of the SNES games with the add-on chips don't work properly, and some of the larger games (48Mb HiROM dumps) get a little weird sometimes or just don't play.If only there was a way to have an icon per system on the Home menu for injects. I honestly would rather have stability and compatibility of injects, than the fancy features of an emu.
Speaking of SNES, VC, and injects, are pretty much all games working?
I've not ran into any NES game I haven't been able to play yet.
As for having a single icon, what I did was this... Put all the VC titles for a specific console in a folder, then use GYTB to change the folder icon to whatever you choose. I chose pictures of the consoles respectively. You can check out GYTB here:
https://gbatemp.net/threads/release-gytb-custom-badges-made-really-really-simple.404355/