I'm not sure what would make USD a good exchange format. The features that make it good for VFX are not something FormZ could make much use of.
I would prefer if Autodessys tightened up existing formats or added IFC support. Unfortunately, IFC is a big undertaking, so I doubt we will see it come to FormZ any time soon.
FormZ needs to embrace BIM and be a fast content solution for Archicad/Revit etc. Creating BIM objects is tedious work, but FormZ could change that if given half a chance.