I’m not promoting, it, but I’ve seen it said more than once that if you use iCloud on one and only one computer — so it only syncs with Apple’s servers and not with any of your other devices — it should be OK (and any other mixing is asking for trouble). I’m pretty sure the people saying it were at least regulars, possibly mods or maybe even one of the devs. Frustratingly, I can’t find any of those posts now except this one from WhiteNoise Using Version History: using iCloud and Obsidian Sync simultaneously? - #4 by WhiteNoise which is the other way round — using Sync on one only 1 computer for its version history.
I only mentioned it because the poster’s phrasing sounded like they might have had iCloud active on only 1 computer. I wouldn’t normally bring it up when discussing sync options.