Thermal printer on Armbian bullseye printing garbage

In these days I am trying, on my DevTerm A06, to move from the provided OS to Armbian bullseye downloaded from:

It installs fine, seems more responsive and I like it. Only big problem so far is the thermal printer.
Out of the box it’s not working at all. By long searching online I ended up in a configuration that “does something” (prints garbage lines instead of test pattern).
my steps were:

-add deb stable main

-install devterm-audio-patch devterm-fan-daemon-cpi-a06 devterm-gearbox-a06 devterm-thermal-printer devterm-thermal-printer-cups devterm-wiringpi-cpi

-add to /boot/armbianEnv.txt these lines:


At this point I have a device called /dev/spidev2.0, the systemd unit starts fine and printer some sort responds to commands, but not in an useful way.
I have no idea on how to further fix this problem: can someone help me?

Should I also install devterm-kernel-current-cpi-a06 ? (I perfectly know how to manage kernels on desktop PC but no experience at all on embedded)