Hi Knut,
thanks for this information.
I used Rpi 3b with original 7`` Touch panel Version 1 with Volumio 3.
I changed to Volumio 4.073 and tried to install Touch panel plugin 3.6.0.
The installation took a very long time, the panel remained dark.
Uninstalling the plugin was not possible.
This error appeared intermittently: no such file or directory, stat temp/.X11-unix/X0
Thanks to your description, I was able to revive the touch panel.