Im going to try to compile from scratch the latest Bitcoin Core version on Debian 12. I will be using the full ISO which it is advertised to include additional libraries, to be found on their website with the filename debian-12.9.0-amd64-DVD-1.iso. My question is, does it compile well, or do I need to download any additional libraries?
I expect you'll need to download and install some package that not included on Debian DVD ISO file. I recall actual full ISO (which include all package) have size in hundred GB or few TB.
The steps described on github still work?
https://github.com/bitcoin/bitcoin/blob/master/doc/build-unix.md#linux-distribution-specific-instructions
https://github.com/bitcoin/bitcoin/blob/master/doc/build-unix.md#linux-distribution-specific-instructions
It should work, when that guide was last updated only 2 months ago.
I haven't tried Debian, but what you call downloading additional libraries usually comes down to installing a few packages, and those are listed on your link already. 