That would then be a SOURCE-pre-snap-indicator. .. and this would then be called the TARGET-pre-snap-indicator
I love the idea of this - it encompasses exactly what I was meaning - but you've phrased it in a way that makes it so much clearer than I described.
If something like this could make it's way into inkscape I think it would make the snapping perfect !
The mouse pointer might be covering all of them, which makes it hard to accurately select the desired snap source. When using "snap closest to mouse pointer only", you will have to zoom in to reliably control the snap source.
One other other might be to use a keypress like ALT or something, to scroll between possible snap points. With the advent of the tooltip and highlighting of the object that would probably also be sufficient to select even close together points perhaps?
Best Wishes,
Alex