What are you using to transition cameras - Set View Target with Blend?
There is onBecomeViewTarget | onEndViewTarget which might help here. Also, if you need to fire events at some precise moments, you can set up a Timeline with the length equal to the length of the camera transition and populate it with Events on its track. These will go off at specific moments. All in one place.
But at this point you might as well forgo the Set View Target with Blend (if you’re using it) and move the Camera with a timeline and run an event track simultaneously.