In some cases, it can be possible to disable specific components to force an avatar to a specific performance level. This has in fact already been implemented with the dynamic bones limiter, and could also be implemented on many other performance rank components. In fact, many of the actual blocking actions exist today as part of the safety system.
I would suggest that when an avatar is to be blocked for poor performance, it should first be evaluated to see if blocking/removing one of the following components can bring the avatar within the performance limits:
* Dynamic bone collision checks (remove all dynamic bone colliders)
* Dynamic bone components (disable dynamic bones, as per the existing blocking system)
* Animators (remove animators except for the root)
* Particle stats (remove particle systems)
* Trail/line renderers (Remove the implicated components)
* Cloths, cloth vertices (Remove the cloth components)
* Physics colliders/rigidbodies (remove the implicated components)
* Audio sources (remove the audio sources)
Note also that dynamic bone colliders should be removed from stats, as the collision checks stat more accurately captures the performance impact. However, if it is to remain, it could also be handled by removing just the collision checks.