I know how to do that, you set the subvolume as the default one, thus, when mounting, if no options are passed, it always mounts that subvolume as root.

But, you have to disable that. Sure, I set it during install, cuz installers are stupid (if you tell it to install in /@, it will most probably moan), but disable it after first run (set the real root as the default subvol, i.e. mount point) and just add subvol mount options in fstab.

It’s just extra steps I have to do now 😒, that’s why the rant.