I've just done a run on West Somerset in the dark and there's no lighting at all on stations or buildings I think this needs addressing at some point
Might be that, since WSR uses the old static “when do I turn on the lights” system, there might be periods of complete darkness as the lights turn on/off too late/early at certain times of the year. Have you tried doing a run at midnight to make sure the lights are definitely on? On the other hand, maybe there’s no night station lighting at WSR because it’s a heritage railway and doesn’t operate during the night? Would be weird if that were the case, but you never know.
At least one scenario is set just after sunset, so lights should work. If they don't, it is a bug and should be reported in the technical issues section.