Event OnBecomeViewTarget questions

I’m curious how this event works and what it’s intended uses are? May assumption was that this would fire whenever an object was “looked at” by a camera but that appears to not do anything.

Is there some documentation for this event?

What is the “best” way to fire events on blueprints I am looking at? I have seen this done with line traces and vector math and such but I was wondering if these were inefficient since I would need to do a lot of tracing to make these items responsive enough.

OnBecomeViewTarget does’t work this way.
This event fires when PlayerController starts to use CameraComponent of this Actor (to “see through” this camera).

Why not to use line trace? If it is about performance, then just not do the line trace each frame.