I use ViaCAD 2D/3D as Michael G. stated and it is an excellent companion for MoI. I originally bought it for making 2D drawings of my MoI models, and realized it woorks great for the variable fillets you are looking for, but is also useful for adding draft and keeping all of these things editable as well.

I use MoI with ViaCAD 2D/3D for all of my freelance design work. A winning combo!

Michael T.