Separate vertical scaling of engine nozzles.

I, as many others, sometimes feel limited by the shape of the default nozzles.
I think this could be greatly improved by a simple slider that adjusts the vertical scale of the engine nozzles.
This would allow more tuning of the shape without having to scale the whole engine. You could make a longer nozzle, for a Nuclear thermal rocket (as an example), or a stubby nozzle for a sea level engine.