Find out which inserters deposit on belt?

[DarkShadow44]

Since the question came up for the Belt Visualizer mod:
Is there already someway to find out which inserters deposit on a certain belt? With bobs adjustable inserters this would get pretty complex to do manually.
Is this something the game even knows like that, or would that require more internal changes?

[Stringweasel]

There is a modder working on something like this but I don't think it's released yet.