It appears that we only receive Events from HAPI_GetPDGEvents after we have called HAPI_CookPDG.
We have a scenario where we would like to load up a master PDG, then drive the cooking the top nodes in the PDG from other HDAs via Python. We can tell from the logs that the cook is occurring, but we will never the results back because we do not receive the Events.
For reference, it will behave as expected after we manually cook one of the TOP nodes using HAPI_CookPDG.
We are currently on version 18.0.498