... but if you get past that, then mounting subvol=@home tries to mount /@/@home rather than just /@home, and the subvolume name is only allowed to be a single pathname component, so that isn't going to work.
... but if you get past that, then mounting subvol=@home tries to mount /@/@home rather than just /@home, and the subvolume name is only allowed to be a single pathname component, so that isn't going to work.