Have Workload Balancer free up hours for users if not used

Description - Have Workload Balancer free up hours for users if not used
Why is this feature important to you – Right now if a user estimates 20 hour on a request, logs 5 hours and the request is either cancelled or completed, the user is still allocated for 20 hours even though 15 hours have freed up. Doing that over multiple requests could free up much time as estimated is always off some.
How would you like the feature to work – If a user estimates 20 hours and logs 5 hours and the request is complete or cancelled, then the remaining 15 hours availability should be freed up for that user to be able to assign additional work.