Would be a good time to distill Switch default pool from LVM to BTRFS-Reflink · Issue #6476 · QubesOS/qubes-issues · GitHub content prior of continuing investing energy under Bees and brtfs deduplication
Meaning: why go BRTFS with bees (offline dedup) if OpenZFS can do what BRTFS but better (compression, encryption) with online dedup (and therefore no need of a background running daemon like bees that dedup AFTER the fact instead of as write happen on FS…). OpenZFS is sooo sexy to say the least. BRTFS performance tests from QubesOS team (offline discussions) to switch to BRTFS are no go…
This would need OpenZFS deployment under Qubes ISO though, which I guess would need its own efforts and not waste efforts on going sideways. Agreed that Ubuntu deploys it (DKMS), while Fedora doesn’t take a stance there and where Oracle didn’t change licence even today. Will need participation in other threads; not this one.
ZFS pool as of today exists. But instructions for install are manual even if really good. Would need to test and convince @marmarek to have OpenZFS inclusion even if Fedora doesn’t take a stance 
@Rudd-O : Can you point to the conclusions (read your articles) that could make QubesOS budge on considering integrating OpenZFS into the QOS installer?