Encountering significant script execution time on StateMachine.advanceStateMachine and StateMachine.getReportedEventCount

We have a scene in which we are sometimes displaying several animating characters at once on a UGUI Canvas set to worldspace render mode. On modern desktop computers with fast CPU's, we are encountering significant CPU usage resulting in framerate drops from 60 to 40 with around 10 characters on-screen. On iOS and Android, we are seeing far worse results, with noticeable slowdown even on 3 or so characters. The majority of CPU time is spent within two function calls to the native libraries:

StateMachine.advanceStateMachine specifically hits high CPU usage during LateUpdate

StateMachine.getReportedEventCount spikes CPU usage during Update

We are observing the issue with the current Unity package release (0.3.9-canary.57), as well as with the latest tag (v0.3.9-canary.170), which we pulled down manually and integrated for performance comparison tests.

Start by profiling StateMachine.advanceStateMachine during LateUpdate and StateMachine.getReportedEventCount during Update, comparing the 0.3.9-canary.57 release with v0.3.9-canary.170. Reproduce the scene with multiple animating characters on a worldspace UGUI Canvas across desktop, iOS, and Android. Done means the reported CPU spikes and frame-rate drops are substantially reduced.