So far as we know, most of the small steam developers have declined to do anything with TSW while the core remains in such a state.
Hasn't someone proudly announced a BR 99 with Brockenbahn a few months ago? I remember the promotion text.... But then it was always announce and cancel, announce and cancel... probably just attention seeking.
Maby tsw 5 will fix that but unlikely. But hopefully someone will still try to do it because I don't think I will get easier in the future to get good references for steam engines