Andy Hine hasn't got the best rep these days from what I have heard. Apparently he has a habit of shouting at staff
I think you are probably right, assuming by build off you mean use the original designs as a reference point. I would imagine Stengel would have the CAD modelling rights though, surely? Given that they relay most of the maths and tchnical specs to B and M.
I can't imagine the process is that easier. Despite all the technological advances we have had in steep shaping, it's probably still very easy to go wrong and deviate from cad models when shaping and testing the steel used to make the track. But CAD software has made leaps and bounds since the 90s, so it's probably a faster process now I guess, as the software is probably capable of giving the fabricators more information.