dunno if this will help, but here is a way that I use overlap and line trace together in my project:
for a very simple AI detection system, I have a sphere collision set to overlap with just a single custom channel.
When the player pawn overlaps it will send an interface call to the owner of the collision. Then the owner will start shooting a line trace to the player pawn to check and see if there is line of sight, what the distance is, angle, etc etc. ALl of that information you can get from the line trace but not from an overlap.
On end overlap will tell the timer shooting the line trace to stop.
I use the overlap basically as a way to toggle the line trace on and off rather than having it go constantly, or otherwise using tons of line traces to sweep a large area.