The spiritual successor to my undocumented and deprecated mod that i still used for each run:
https://mods.factorio.com/mod/x-stacks-ltn-combinator-helper

Any item signals get outputed multiplied by their stack size on whichever color of wire.

Fluid and virtual signals are effectively ignored. (as in: does not get outputed at all)

Whilst editing the combinator a "wrong" amount or stray signal might exist for one tick.

This mod has no performance overhead other than when any player has the gui for it open.