Hello piero-la-lune, thank you for the mod.
What is it like to reach a distant outpost?
Does it need a radio signal because of the distance, or do you have to build a long line?

Can the Dispatcher be used to build a large waiting station for all trains, and if any resources are needed and offered, will the train be sent?

Example:
Refinery A needs iron.
Mine B has no iron - train is waiting / Mine B has iron - train picks it up, brings it and drives back to Zentral Station ??
This concept would be interesting.

Yes, I believe one of the main usage for the dispatcher is to build a large waiting station for trains (that is how I use it).

When an outpost is low on some resource (iron plates for instance), or when it reaches a certain level of some resource (iron ore for instance), it requests a train to the dispatcher.

As you said, it requires to have your outposts and the waiting area connected with a red or green wire (I believe there is a mod for wireless signals). Also the signaling logic is not so easy to implement, but it is possible (I did it, I may post the bluprints at some point)

Thank you for your answer.
I will try it and look forward to it. Thank you.