The card is really fast, it's a Samsung uhs1.
The box boots really fast, just a few seconds to get ssh.
No gui starts, unless i manually start kodi and then the games gui comes to life and they start fighting.
If i manually try to start (like kodi) emulationstation or retroarch by:
"touch /var/lock/start.games" or "touch /var/lock/start.retro" followed by "systemctl start retroarch or emustation"
but before i start kodi, nothing happens. Both games gui's come alive only if kodi is started.
Weird...
PS
I like your approach better because it (can be) more complete.
My guess is (since it works on your end) it is a strange box compatibility problem.
Perhaps it can be fixed if i compile it from scratch using minimx 1gb dtb and settings (add it as a new S905 device).