Combine Kopia with file based encryption

Unfortunately it’s no longer possible to switch off encryption for already encrypted source files. What about combining the genious Kopia with programs like gocryptfs, cryptomator, cryfs…?
therefore not only the snapshot should be encrypted, but all source files in the repository. If the user wants to work with it, he must mount it as a local filesystem, like mounting snapshots. When mounted, files are added by encrypting them on the fly.

And what would be the benefit of that exactly? Kopia doesn’t have a glimpse of knowledge about the underlying fs - it gets the source files decrypted handed to it. If you’re talking about snapshotting an “encrypted” fs offline, where you come across the encrypted files themselves, I’d say that Kopia is not the right tool to use for backing that up, or at least Kopia will not be able to play out all its strengths, since you Kopia doesn’t get any actual contents it can use the deduplication algorithm on, due to the encrypted files defeating the content-addressable-storage setup.

It should be irrelevant when Kopia encrypts files, when the file is created or during snapshoting. So the original source data should be “snapshot 0” and every file exists only encrypted. But when snapshot 0 ist mounted, kopia and users can work with it.
I don’t know how kopia works and if that would be possible.
The benefit of it is, that you have encryption and Backup in one program. Kopia forces the User to encrypt on Google Drive, so why not encrypt the source files? I don’t speak of file system encryption Like veracrypt, but file encryption.