If you’re not intending to use complicated RAID setups, just go with btrfs. There is no reason to bother with zfs given your specs and needs.

Do not go with ext4. Unlike both btrfs and zfs, ext4 does not do data checksumming, meaning it cannot detect bit rot (and obviously cannot fix it either). You’ll also be missing out on other modern features, like compression and copy-on-write and all the benefits that entails. Once you start using snapshots for incremental backups using btrfs send (or its zfs equivalent), you’ll never want to go back. Recommended script: snap-sync.

Initially I was using rocky+podman but inevitably hit something I wanted to run that just straight up needed docker and was too much effort to try and get working. 🤷

As someone who’s used Podman for a while, though possibly not as extensively as you, what was it you hit that needed Docker? So far I’ve gotten everything to work with Podman, though sometimes I’ve had to RTFM and specify some extra command line parameters.