Hey there @PaulJeffsMT! So to clear some confusion, PhysX was the older physics engine, any time you see it, it’s going to be for mostly legacy stuff in modern versions. Chaos is the current physics engine.
From what I gather, AsyncPhysicsTickComponent doesn’t let you mess with the physics between the initial steps, so without an override like you mentioned I don’t know if that will work. I think FCalculateCustomPhysics is the closest equivalent to Unity’s FixedUpdate but I’m not finding a super concrete example.