Essentially another addition to the dubugger which would allow you too see a live simulation of a script with some kind of animated visual flow for the events’ branches. This will help with testing things and squishing bugs much faster than simply setting up breakpoints to bring up a script.
Perhaps the ability to edit the script in real-time as well would be even more helpful, if that would be possible without requiring major engine changes.
Below is an example screenshot taken from Unreal Engine 4. Arrows added by me to indicate motion.
Real-Time Visual Script Flow Debug Tool