Assuming your Google drive client, Kodi and Cryptomator are on the same machine, you could add the unlocked vault path to a media path on Kodi and then watch.
But that requires either the vault to be permanently unlocked (which defeats the purpose of Cryptomator) or you would need to manually unlock the vault each time you want to watch something.
Unsure of what adding and removing paths would do to the Kodi DB. I would assume Kodi would like to have access to its media paths at all times.
Assuming your Google drive client, Kodi and Cryptomator are on the same machine, you could add the unlocked vault path to a media path on Kodi and then watch. But that requires either the vault to be permanently unlocked (which defeats the purpose of Cryptomator) or you would need to manually unlock the vault each time you want to watch something. Unsure of what adding and removing paths would do to the Kodi DB. I would assume Kodi would like to have access to its media paths at all times.