I am more interested in seeing astro train number scale with AI difficulty and AIP.
The only things the astro trains really damage are the mines, and these have become very cheap recently.
They pose some threat maybe a few hours in game at most. Later you can completely ignore them - they deal minimal damage, and its not very common for a train to appear in an important large battle to mess it up.
Plus, since they are not ever replaced, their numbers diminish slowly, as you can just harass them with your fleet whenever a train passes by your idle fleet, and the trains cant repair.
Also, the role of train stations/rerouting is not important enough right now, as even clearing the nearest stations may still result in trains passing through your system when going between distant stations. I wish there was some sort of way to see the train routes and get some idea how they can be rerouted.
Hell, it would be awesome to be able to hack train stations and manually modify the routing related to the given station.