Resource levelling / capacity-driven scheduling

I've had a number of discussions with clients about the ability to level resources, which is something MS Project has offered forever. In the context of RM, where the capacity view currently just reflects task assignments based on the project schedule logic, some clients would prefer to have their resource capacity considered as a ceiling and not allow over-allocation.
I appreciate that neither Smartsheet nor RM are architected to offer the flexibility to change how resource scheduling is driven at this time. However, as it's a recurring question, and I couldn't see any other ideas submitted on this topic, I thought I'd log it.
Essentially, I would expect there to be the ability of an admin (probably a resourcing admin in RM) to switch to a different scheduling 'engine' that takes capacity based on roles/disciplines as a fixed ceiling and drives schedule changes in projects to optimise the delivery of tasks synced from Smartsheet, without exceeding the ceiling.