In your steam library:
- right-click the game
- select properties
- select general
- find the steam cloud section and uncheck "keep games saves in the Steam Cloud for Baldur's Gate 3" (if you don't have anything, you should see "0 bytes stored")
Thanks Bob, as Ive been a little concerned about this, I posted my concerns on Salo's post today.
mine says: O bytes stored/18.63 GB available