Well, I don't know if this is a good place (or the place at all) to post stuff like this, so I apologize in advance if that is not the case. Here goes anyway.
An idea I had, prompted by other things plus real trains. The player is positioned directly in the middle of the locomotive. In a lot of cases, this makes it more difficult to see out. See below:

A lot of those locomotives' models have smaller windows on each side, but now way to see forward out the middle. My suggestion is (if possible) to allow a player movement (or tilt, if possible) so that it would be possible to see out. Basically, when the player presses a certain key, then the player would move a certain amount to the left or right a certain amount. Alternatively, if it were possible (which I kinda doubt), tilt the player model so that it would appear as though they were looking out, and still appear mostly inside the engine model. If anything here is confusing, please let me know, I'd love to explain!

It may be possible to move the camera itself to make it appear to the player as if they are leaning out the side or something.
Tilting the player itself I'm not really sure would work...

Good to know that the mod isn't quite as badly coded as I thought. Hoping for this in some release at some point. :P

Anything along those lines would be amazing. Even though with some trains it wouldn't be nesasary, I would say have it apply to all of them, if that is a choice you have to make. I haven't read through TC's classes...

Well it would be easier to apply it to all of then since it could be done in the base locomotive class, which applies to all trains.

Well. It's carried over from 1.6.4. Something to deal with later.