I help myself ....
If you install pixeldesktop and pikiss and vulkan driver on retropie (now I had upgraded to retropie 4.8.2 )you can simply integrate lr-ppsspp vulkan driver support installed by pikiss simply editing es_systems.cfg and add a new system called (for example) ppsspp vulkan and edit the command line to execute with xinit lr-ppsspp (from the new directory created by pikiss)...
So retroarch in emulationstation remain the same (without vulkan support) but when you execute from emulationstation the new emulator lr-ppsspp vulkan driver supported is correctly launched and executed ....
You don't need to install retroarch from pikiss because retropie won't see the new retroarch...
Yes this is a (great) trick ...but works on
Duckstation and lr-ppssspp installer by pikiss (with vulkan drivers) and launched from emulationstation with desktop initialization thank to xinit command before the launch script of every emulators...
You can watch my solution
