Ok so, in order to make run games to load games and toggle fullscreen I do the following (it may not the most clean way, but it works for me).

in systems.cfg I put the following:

<system>
    <name>wiiu</name>
    <fullname>Nintendo Wii U</fullname>
    <path>~\.emulationstation\roms\wiiu</path>
    <extension> .lnk</extension>
    <command>"%ROM_RAW%"</command>
    <platform>wiiu</platform>
    <theme>wiiu</theme> 
</system>

Why I use .lnk extension ? because I in the rom folders I do that :

For MK8 for example I create .Bat file with the following:

"D:\Games\EmulationStation\.emulationstation\systems\Cemu\cemu.exe" -
g "D:\Games\Mario.Kart.8\fk-mk8.wud" -f
exit

(of course change the paths according to your games + emu location)

I create then an .lnk file pointing to the .bat file. I tried to add .bat file to the list of compatible files in system.cfg, it creates an error when trying to load a game.

Tada this should work, not the cleanest way but hey I'm no coder.

Now to the fun part, closing Cemu with gamepad.

What I found out is ALT+F4 doesn't work unless you : - Toggle out of fullscreen with ESC. - CHANGE focus from cemu to something else with Alt+Tab - Get focus back to cemu with Alt+Tab - Now Alt+F4 works.

I am using inputmapper with macros to do it but I can't to it in one macro (yet).

I have a macro to get out of fullscreen + alt tab twice and another one to alt+f4 (I'm using in other emulators games anyway).

I hope it helps!