I've used Rclone with Proton Drive to mount a directory .... it is dreadfully slow. Maybe directory/file sync (where copies are both places) are better.
I cannot recommend Rclone for Proton Drive in "mount mode" currently.
@protonprivacy This is why I'm still using Tresorit on Linux .... One of two reasons (the other one is access to shared folders with read/write access).
@Dave It actually works quite nicely with Tresorit. And the latency lag is acceptable.
I've been doing this via Rclone + Jotta Cloud with Rclone encryption, which still works better than Rclone + Proton Drive. But not as smooth as Tresorit. Rclone + Backblaze B2 + encryption is also better than the Proton Drive approach.
I've also used this approach in read-only mode with @borgmatic too, which is a great way to restore data from a backup. And that's almost as smooth as Tresorit (even though a very different use case).