As far as I can tell and test, the Tick Task Manager will delay execution of new tick functions spawned during Pre Physics to Start Physics, even if the tick function was registered for Pre Physics. Because the physics tick has already started in Start Physics and there is no way to know if the delayed tick function accesses the physics scene, this sounds very scary to me.
I see there is already some code in FTickFunction::QueueTickFunction() to avoid scheduling delayed tick functions in the During Physics tick group. I think this should be expanded to handle the Start and End Physics ones too. Could you guys please have a look at it? The codebase I’m working with is GitHub 4.7.3-release. Thanks!