I think I may have found a bug in this mod:
If you have an existing train line, remove one station from it (I mean remove the station from the map not the schedule), rebuild the station and give it it's original name, then the station is added back in the line schedule and everything looks normal, BUT in the rules section of the line the checkbox "Signal #" is not working correctly anymore.
The checkbox is still checked (as it was before the removal), but the train will not go to the station, which signal number is applied to the lamp, it will go to the next station in the schedule. You have to uncheck the checkbox, save the line, check the checkbox, save again, then it works.
Not sure if it's maybe not "supported" to remove and add stations from existing lines this way, I just stumbled over this issue(after 2 hours of uneccessary debugging of my signal network) and couldn't find anything about it...

I confirm experiencing this bug, thanks a lot for posting the workaround of uncheck-save-check. I'm currently doing an Angel's+Bob's mod factory with a central combinator setup to automatically send the train at any station in the network to a suitable station in the network. I noticed that trains leaving my most used station just went to one without any need for service, then from there to yet another one. Both departure stations had been upgraded from regular station built before I had the required circuits for ST stations, being lazy, using a copy operation with a temporary ST station to transfer the exact station names. I guess these two had also been accidentially checked in the list before upgrade, as I had inserted some stations before them in the schedule and the "Signal #" check mark seems to be tied to the station number, so they had gotten the check marks from some other stations. Anyway, my train network would not have been possible without Smarter Trains, so big thanks to Choumiko, great work!