I think it would be cool with the new seat management feature that permission sets could be configured and if a seat is added to the persons that it remains the permission set but has added “sales enterprise seat” attached.
I have to create each role in duplicate - one where they have sales enterprise or other seats, and one where they don’t. This causes a lot of permission sets to be available. Something easier where you can have base permission sets, but the seat allocated can be added on top and not disturb the original permission set.
The reason i want this i have a strict policy that each user must be on a permission set and not on some manual configuration for access controls.