How to find out when a level begins streaming in?

Hi all,
is there a way to learn when a level is starting to stream in? I may have to react to that and stop some processing until the level is completely loaded. Additionally, is there a way to learn when all current level streaming have terminated?

I was looking if I could get an event when a character enters a streaming volume, but there is no way. So I was already thinking about using simple triggervolumes and then handle streaming manually, but that would be a lot of work for something that could be done by the engine with two simple events, so I wonder if there is any way to find that out

Thanks