For what it’s worth, I do think OCIS is worthy of switching to if you don’t make use of all of the various apps Nextcloud can do. OCIS can hook into an online office provider, but doesn’t do much more than just the cloud storage as of right now.

That said, the cloud storage and UX performance is night and day between Nextcloud/Owncloud and OCIS. If you’re using a S3 provider as a storage backend, then you only need to ensure backups for the S3 objects and the small metadata volume the OCIS container needs in order to ensure file integrity.

Another thing to note about OCIS: it provides no at-rest encryption module unlike Nextcloud. If that’s important to your use case, either stick with Nextcloud or you will need to figure out how to roll your own.

I know that OCIS does intend to bring more features into the stack eventually (CalDAV, CardDAV, etc.). As it stands currently though, OCIS isn’t a behemoth that Nextcloud/Owncloud are, and the architecture, maintenance is more straightforward overall.

As for open-source: OCIS released and has still remained under Apache 2.0 for its entire lifespan thus far. If you don’t trust Owncloud over the drama that created Nextcloud, then I guess remain wary? Otherwise OCIS looks fine to use.

2-2-1 still insinuates having a remote backup. I don’t see how this particular threat destroys a 2-2-1 setup.

I have been utilizing BunkerWeb for some of my selfhost sites since it was bunkerized-nginx. It is indeed powerful and flexible, allowing multi-site proxying, hosting while allowing semi-flexible per-site security tweaks (some security options are forcibly global still, a limitation).

I use it on podman myself, and while it is generally great for having OWasp CRS, general traffic filtering targets and more built on top of nginx in a Docker container, the way Bunkerweb needs to be run hasn’t really remained stable between versions. Throughout several version upgrades, there have been be severe breaking changes that will require reading the setup documentation again to get the new version functional.