I am well aware that RedoxOS uses ZFS. While this is great it consumes more RAM compared to HAMMER2. HAMMER2 is the equivalent to ZFS afaik and it consumes less RAM so I wanted to suggest to use HAMMER2 instead. It is used in DragonFlyBSD.
AFAIK, Redox uses RedoxFS. Where did you read about ZFS support?
Something advanced like ZFS/HAMMER2/btrfs would be useful long-term for sure.
ZFS is certainly not supported. There was once an attempt to rewrite ZFS from scratch in Rust, but it was ditched in favor of RedoxFS / TFS. The end goal will be to use a file system written in Rust as the default file system.
I actually saw it in some screenshots so I thought it uses ZFS.