can we get a hook to cancel out OnPhysicsNeighbourChanged in StashContainer

One thing you could try is to add a component that also defines OnPhysicsNeighbourChanged, in which you check for and cancel the DoOccludedCheck invoke. May have to do NextTick(fn) or Invoke(fn, 0) in case the component's method is called first (easy to test and find out).

ya its what i am doing now is checking DoOccludedCheck for invoke and cancel it but would like to not check it all the time and just cancel it when its called.

My suggestion above should only require you to check it when it's called, since the component subscribes as well.