The Global Shape by surface by using the single base surface and edit poles does offer a good solution. I am trying to tak it to the next stage where as % of change to the poles differs based on the size.
Is there a way to parametrically control the base surface with the same percent of change to the poles between largest to smallest size.
you could try gobal shaoing using difference between two surfaces with the surfaces being constructed from sketches. It will probalby not be precise but at least close to predictability of most processes and controlable.