Thank you for reporting back. I am happy to hear you were able to find another way to solve the underlying issue without needing the v4l2loopback-dkms package anymore. I see you already have backports enabled but probably with low priority (as you should) by default. You can check "man apt" for information how to install that specific version (or use aptitude like I do). That being said, "sudo apt install v4l2loopback-dkms/bookworm-backports" should probably get you the version you need and hopefully it would install fine.

sound is a gotcha on the opi z3, actually opi z3 has sound but output only. accordingly opi z2 has sound both input (mic) and output. and i think for 'convenience' many would after all use a usb sound card instead, just that there is only one usb port and the other 2 is actually on the extension pins on opi z3 as do with the audio output on z3 http://www.orangepi.org/html/hardWare/computerAndMicrocontrollers/details/Orange-Pi-Zero-3.html as for usb + audio extension, orangepi sells an extension board but that accordingly without that it may be possible to hack those usb connectors https://www.aliexpress.com/w/wholesale-usb-female-type-a-with-wire.htmll

Thank you for the report and this indeed does look like a general bug. It appears as if this comes from the file 10-armbian-header and in particular line 199 or possibly line 214, but I cannot look into it further right now. It's probably got something to do with network not being configured at the point at which you encountered this. I do certainly encourage you to open a ticket on github with the first entry on the pulldown "bug report for the armbian build framework".

SBC Orange Pi Zero V1 is still a popular SBC and is still sold on the market, among other things, because it has an integrated sound card and for this reason, a lot of hamradio operators still buy this model because it allows you to build very compact mobile hotspots without having to attach a USB sound card protruding outside the housing and that is why it is very popular and still sold despite the fact that versions V2 and V3 have been released, so it is not an SBC that has completely gone down in history.

I haven't tested this... but I see that pins PH1, PI11, PI14 are not connectable in the orange pi zero 3. Only PH3 would be connectable. Is this correct? Is there an overlay to get PWM in PH2? (i read in the post from April 5 that it can be a PWM pin)