I’m not sure what are you trying to achieve, are your vaults in different devices?
I can share my experience with that.
I have two vaults (pc and mobile) , I sync all the folder through SyncTrazor automatically when they are in the same network. If I open both vault at the same time and make changes that needs to sync, it shows a “workspace - conflict” other than that it’s been fine.
Is the B vault a backup? If so I have my main vault on the iCloud so I’m able to work from any of my devices. My second vault (backup) is on GitHub and I use Git Commit to push changes to my backup once a day.
I had a colleague get a ransom ware attack a few years ago. We were sharing a Dropbox folder and all of the shared documents were encrypted including the local folders on my computers. Since then I haven’t used an automated script for my backups. It’s not much help to backup corrupt files.