Suggestion / Idea ECS Physics/Graphics Support

[Jawsarn]

... matching the rigidbody engine's (PhysX or Unity Physics) temporal fidelity.

This is not correct. As I noted above the Unity Player Loop, PhysX runs on FixedUpdate, while Unity Physics runs in Simulation Update->Prediction->FixedStep.

But that one idea is similar otherwise. I just can't assume that FixedUpdate and Unity Phyiscs FixedSteps match up.
Maybe one could do a longer delta for multiple fixed instead of looping it, but that's just optimization.

For that option I think in the end one would want a Synchronization type of Manual and be able to call the methods manually, and some of the LateUpdate to be extracted to a method to be called with custom delta times.