I agree with the “fine tuning” approach, but I guess the mount command will handle most scenarios automatically.
Before implementing, let’s see if mount does its own job 
But id someone want to try to open a PR, the steps should be:
- create a new pop for managing protocol version
- refactor the mount/umount actions to handle the new parameter (also check the is_mounted function)
- add it to the Cockpit API
- expose the new options inside the Cockpit UI
- document everything