Yes, i installed it a few hours ago AND KODI GBM is compiling right now !
I also ran your script and it went fine BUT your KODI GBM does not start sadly and i do not know how to troubleshoot it because i do not know where to look at... if i understood correctly, KODI GBM must be launched from a terminal session without any X server running right ? When i do this, my SBC is freezed and i must AC unplug / replug it. I also tried to launch it though a systemd service and it does not happen anything BUT my SBC does not freeze in that case... you will find it below...
Description=kodi-standalone using GBM
After=systemd-user-sessions.service network.target sound.target network-online.target
SupplementaryGroups=audio input video
ExecStart=/usr/bin/dbus-launch --exit-with-session /usr/bin/kodi -- --windowing gbm --standalone
Anyway, thanks for your assistance and congratulations for your work, you did very well !