I hate to reply because I don’t have the answer to your question, just a remark which you may not care for: why bcachefs, especially on fedora server which has a rapidly advancing kernel? Bcachefs is out of the kernel tree. It is just going to be a constant maintenance burden on you to upkeep it with your server.
Btrfs will support subvolumes, compression, nodatacow directories, and everything else you might want while not being a thing you have to manually keep up with.
I would not expect the fedora installer to have any support for bcachefs, because fedora doesn’t have support for it generally.











This is a strange statement, because it’s now a mature fs that works. It’s even the default fs of the OS you’re trying to use. But for the sake of experimentation, I can appreciate wanting to try something off the beaten path. And I generally agree about Oracle and, specifically, Larry Ellison.