Remember Me
How about the idea to define a default emulator (e.g. MAME) and Game as default? To directly launch this after the boot?
https://github.com/RetroPie/RetroPie-Setup/wiki/FAQ#how-would-i-start-from-command-line-say-the-snes-emulator-by-itself
and you would need to launch it before emulationstation – via /etc/profile.d/10-emulationstation.sh etc