I did not switch the VM from OVMF to SeaBIOS after installation.
I did not resize the Disk as it was a new install.
I don't know what scrubing the ZFS pool means. I did not run commands. Maybe Proxmox did something?
I don't know what thin provisioning is.
The pool is brand new and has lots of space. It is 15TB. Their are no other things being stored as this is a fresh proxmox install.