Replaced my third system with artix and could not be happier.

I’m not sure I really understand your use case, but OwnCloud and OpenCloud offer fewer features than Nextcloud and are mostly about file sharing.

Other things you could consider: pydio cells, or Copy party (very simple and more just cloud storage, no syncing).

Or Netbird, both work very well and Netbird can be completely self hosted; Tailscale requires Headscale AFAIK.

I have indeed seen that XO-CE script. But is it true that you have to delete and recreate the container, rather than just doing apt update? AFAIK XO_CE is just a debian VM.