External users require System Admin approval to become provisional member
Options
Currently external user can become provisional member based on permission granted by the owner of sheet. This access granting should be controlled by System Admin based on an approval process. Otherwise it'll be very difficult for System Admin to monitor the seatings as well as providing inconvenience to users when needing to downgrade their seats.
Proposed idea:
- Owners can only assign external user as Viewer or Guest.
- System Admin to control if external user can setup as provisional member