You probably had a go at cold and dark startup of a locomotive during the introduction most likely or rarely in the scenarios. Doing the shunting activities with the BR 363 for example is a very memorable session because you are working with a very old, old, old, old locomotive. So why not get the full experience and start it up two. The feature I am suggesting is a CORE feature, It's suppose to enable cold and dark to any locomotive you have there on demand. But use it wisely otherwise your scenario could cost your action points. This would be perfect for all the shunting activities mostly but other instances two. I am not expert on this but It's probably going to be not easy. One last thing, we'd need the typical walk-through for the cold and dark mode to make sure we follow it up properly. This should have the option to be disabled if you mastered it after awhile.
Excellent idea and I tend to do this with DB BR363 Sand Patch Grade CSX SD40-2 & GP38-2. When starting a service perhaps they should extend this to Electric locomotives too
In the UK at least there are very few instances where a train would be left totally cold and dark. More likely the loco would be set up at the depot by an engineer and the unit would be ready to go with a short setup. Maybe some freights would be better left C&D but passengers? Less likely