I can’t remember exactly, but I think the only problem was that you can’t (or at least I was not competent enough) add existing markdown files which are already in nextcloud to the sync process. So instead I added the empty named markdown files in obsidian, triggered the sync, and then populate each file on the desktop. And I was very picky about my folder/vault naming because of my desktop setup (and the rest of my cloud structure), but generally it is really easy to set up if you have tried it once on some dummy data so you don’t accidentally ruin something.

I do not use any"thing" apart from the aforementioned sync plugin (called ‘remotely save’), as I am very standards compliant with my stuff. But I think the editor is very extendable in comparison to other android options.