You also need to factor in the following on seat maps

1. All of the E+ seats will look look like they are taken unless you have access(are elite or bought access) to sit in those seats
2. Exit rows will look like they are taken unless you are 1P or 1K
3. Middle seats next to elites will look like they are taken even though they may not be.
4. Not everyone has seats assigned to them yet
5. With the new seats rolling out, ua has started to block out rows that arn't common in both configurations until they are 100% sure whether you'll get the old or new layout

Moral of the story is that their are very few ways of knowing how many seats are left until all buckets are 0 (on seat counter). Their are, however, a couple of ua employees on the board with this access to the loads who don't mind looking them up from time to time even thou it's unofficial.