Hi, as you mention balenaOS does not currently support customization kernel command line arguments. The recommended approach is for the user application to unload the graphics driver and reload it with the appropriate parameters before launching the graphical application.
The process would look something like:
- stop plymouth with Dbus before graphics driver is used
- possibly disable virtual console echo 0 > /sys/class/vtconsole/vtcon0/bind
- rmmod {driver} / modprobe -r {driver}
- modprobe {driver} … (new settings)
Check out the following forum post for a similar example blacklist drivers in host OS - #25 by jgordon.