Unmount does not stop bcache

[Atemu]

I have an external disk that I stupidly formatted with bcache (atop of LUKS).

Unlocking and mounting works fine and udiskctl interactively prompts me to escalate privileges to activate the bcache.

When attempting to do the inverse however, it unmounts fine but then can't lock because the bcache is still active. I then have to manually figure out the associated bcache device and then manually write a magic string into a magic file.

Unmount should have at least the option to stop a bcache again or perhaps even do so by default as mount does too when performing the inverse operations.

Speaking of bcache: Is there a reason why I'm even prompted for privilege escalation here? Isn't it the whole point of udisks to allow unprivileged users to mount disks in a standardised abstract manner?
There also generally does not appear to be any documentation regarding udisks interaction with bcache which I found quite confusing.