The Scheduler/Workload Balancer lacks fundamental functionality. It allows you to filter out only parent tasks. It should allow you to filter out certain tasks all together. Example, I might have a project with 150 tasks. However, I only need to schedule resources against 50 tasks. There should be some kind of attribute that can be set at the task level where the system would include or exclude from the scheduler. Unfortunately, this has been a deal breaker for our department. We are looking outside of Workfront for a scheduling tool.
