hi, i'm using the mod with LTN train and sometimes, train that are completing an LTN task are called while loaing or unloading.

this makes me think about the possibility to add options on train call, like if the searched train should be empty or not and what train color to call.

this way it's possible to have more granular control on what train will get called, for example a player could use a color to identify artillery train, one for cargo, one for liquid and one for train with only the locomotive

if you are interested in adding this option, maybe add this window to a different keybind, so one could still choose to call a random train or a more specific one

Avoid setting shuttle functionality on automated trains. I have extra trains for the task to avoid the problems you see.
For artillery trains I use the manual shuttle train module. So they do not respond to calls but when riding they can be controlled as the other shuttle trains.

For your other ideas: good ideas, but to be honest they add a fair bunch of complexity and I do not think that it is worth the effort.