Yeah I’ve heard this from a few people with similar setups, Postgres does seem to alleviate a lot of the performance bottleneck from running virtualized for whatever reason.

I've had no problems with the normal nextcloud apache container for the last couple years. I lock to a major version and let it update itself on the minors until I feel like like changing the yaml to the next major. I've gone from 24 to 30 this way without issue.

Actually, I do have to install the contacts and calendar apps from time to time but that's only when I want to use the webUI for them, caldav/carddav has always worked.

AIO is performant and much easier to maintain. If there was a method to try to run Nextcloud in the last decade, I probably tried it, and nothing has compared to the AIO.

I have the docker AIO going for about a year after every other form of install exploded itself. So far so good.

I’m honestly not sure, you’re discussing a few corner cases that I haven’t tried out personally. I think you’d just have to do your own testing to see. I suspect the more layers of abstraction, the more they could potentially slow you down, but can’t say if it would be experienced the same way some of us who ran in docker had observed.

Proxmox is quite powerful, if you get it setup and running smoothly it would be awesome to hear back about how you did it!

From personal experience, Docker is fine. Just be sure to use postgres instead of the default mariadb and you're golden