How to cast to the location of a separate Actor on an input event?

In case there was doubt regarding how to do it with widgets, the project linked above has been updated and you can switch between the 2 - see what fits you best:

Above, the antii-aliased lines look superior, ofc. A neat trick is to draw 2 lines, one on top of the other; the 1st one is thick and the 2nd one is thin:

image

If you make the inner, 2nd line brighter, the whole thing will have more body / volume.