Hi Alano,

> Bummer because there are some forms which are easier to make in Polys and I want to
> work with an engineer who uses ProE. Iges would be a good go-between.

There is a possibility to work like that using the t-splines package. T-splines can convert a the sub-d control cage into a NURBS surface equivalent that can be read into CAD programs and transferred through IGES.

I don't think that t-splines is available for OSX though.

The other thing that you could try which is similar is the sub-d NURBS plug-in for Modo.

But it basically takes a specialized converter to do that route.

- Michael