OK, thank you, please excuse my relative n00bness in armbian matters, but where do I find the .deb packages that make up the image? E.g. if I want to install the same kernel than this image on a Debian install, for that I need the .deb package. To see what is in there source-wise, I'd need e.g. the .dsc file and the files referred therein. If I want to see what version of userspace tool protection-domain-mapper it uses and/or install it, likewise I need to get the .deb file and the .dsc file.
I mean according to the documentation at https://docs.armbian.com/User-Guide_Getting-Started/#how-to-update-firmware-and-packages, after the image is installed, the way to upgrade to newer versions of everything (within a major release like bookworm or jammy, not across them) is a Debian-standard apt update and upgrade. So all this must be in some APT repository somewhere?