Hi,

First of all - thanks for this amazing mod, it was really amazing coming from vanilla playthrough and getting ability to summon a personal train without having to go through a lot of hassle of tracking it down/placing it down etc. A really amazing addition.

I am aware of the limitation regarding the changing train IDs (partly because I just poked around a little bit to understand how/when it happens), but I was wondering if it would be possible to keep track of such changes via the on_trian_created (https://lua-api.factorio.com/latest/events.html#on_train_created) event.

From what I have seen, every time you attach an additional wagon to the train, the game will first create a temporary train, triggering first event with temporary train object and old_train_id_1 and old_train_id_2 set to nil, and then it will merge the old train with the temporary one, triggering a second event with new train object and setting old_train_id_1 and old_train_id_2 to old and temporary train IDs (not 100% sure what the ordering would be).

Thus, by registering with this event, I think it should be possible to keep track of personal trains across attaching/merging of additional wagons.

Does this make sense? I'm not so good with Lua, but I could probably try to have a look at the code and try to submit it to you if you would find such addition and help useful.

Best regards,
Branko