TL;DR
Give train stops the ability to read train wagon types of a train that's stopped at the stop (not headed to it)What?
Example: When a train made up of three normal locomotives and a single rare cargo wagon stops at a train stop it would produce a signal of 3x[item=locomotive] and 1x[item=rare-cargo-wagon]Why?
Without being able to read the wagon type making mixed dispatch stops is most likely not possible. This is my last hurdle to achieving a fully universal train network. (with how the game works currently fluid and solid trains require separate dispatch stops, I can't distinguish empty fluid trains from empty solid trains when using signals)This would also have an interesting side effect of allowing the player to lock a train below X quality in a stop so it doesn't re-enter the network