if you’re on a dev/community build and can do adb and some commandline, this is an option, if on stable, this will work. There are also other ways via a recovery / twrp to get at the file, see other answers in the thread.
The author suggests to share each note as backup. While you can also multiselect / select all notes, they will be fused into one share text - this should be the easiest way to have peace of mind.
Long term I’d move away from this notes app if you can and just use a (markdown) file-based app
Thank you very much! I just used the multiselect/share trick for now.
I know a Markor & Syncthing solution would probably suit my needs better, but so far I was just lazy enough to use the system notes app anyway. Unless sync would be back all of a sudden, I will probably be motivated to actually switch within the next weeks - with the abe script you mentioned the process looks straightforward enough.