They probably could, but would it make sense? Probably not so much, as the 403 never was in Aachen and as far as I know there was only one IC service to Aachen in the past. I believe today there are none…
For DB BR101 the only time it will run there if it needs to do the Sleeper train job is if DB BR182 OBB1116 have technical issues. There's the 07:15 trip & the 19-21:00 trip.
It could be ai only at köln and you could possibly do a service from the depot and same for the br 101
Aha, yes, of course! More AI would always be welcome. It was not clear from your reference to the very minimalistic headline that you were talking about AI. I assumed you wanted more driveable services, like probably anybody else as well The 403 would still not make a lot of sense as AI, in my eyes, as the 406 has basically the same visual model and it would make more sense to use this model, as everybody would be able to actually see it who drives on SKA. For the 403 you need another DLC (HMA). I like the idea to make the depot busier! Not quite sure they will layer a separately available loco DLC, like the 101, for a 5min service, though. At the end of the day they have to invest money to do this and want some return for it. I would certainly not buy SKA when there would be a couple of 5min services added for an addon which I may not even own.
I agree because the one from HMA has a green stripe which would really fit so I think they can just make ai 406 and if not I would be disappointed but I would be OK with a 403 layer