Should maybe add some context in the off chance someone reads the above.
I've used vanilla Debian for server/nas/desktop needs for almost 30 years but am now forgetting things, so I'm looking at ways to ease the path for the future and honestly it ain't looking great.
I've never really liked OMV nor Unraid. Truenas is great but I have no need for ZFS everywhere except (maybe) to mirror 2 drives and I'm sure scale allows the flexibility of using ext4/brtfs but I would need to learn new syntax. So proxmox is the go I think but figuring out adding drives to the containers isn't intuitive for me. I want a basic mergerfs mount point available to VM/Containers that'll than be backed up but I can't find anyone else that goes that route.