If you make a very small loop with two stations and enforce a 1 train limit on both, with only one train on the tracks going between them with no stopping conditions it will come to a halt at one of the stops.

I would expect the train to only be able to hold one reservation at a stop at any given ...

Have you taken a look at LinuxGSM?

They have factorio server support now: https://gameservermanagers.com/lgsm/fctrserver/

I like the countdown, perhaps you could make a PR onto LinuxGSM to add some of the functionality of your script?