Thank you Zoomer et al., your answers help a lot...good to know there's really no way to improve the SU-VW transfer and the limitations are essentially with SU.
In Australia a lot of VW architects are using SU for their conceptual modelling then VW for 2D drafting. We're trying to nudge them across to VW for the whole lot. I can see the attraction with SU...it's incredibly fast and the ability to apply a texture by face is very powerful. I'm investigating equivalent workflows in VW. So far the push/pull with sub face is as close as I'm getting to a SU like experience. But of course we produce solids this way and textures will be applied to the whole solid - not a face...so that's a fundamental difference/shortcoming. I'm interested in a continuous pathway in VW from concept solid modelling through to VW objects then (obviously) tech drawings. Using solids we can extract polygons (via the inner boundary - paint bucket) which we can then use to 'create objects from shapes' to walls, slabs etc. It's probably a conceptual ambition to work this way...and questionable as to whether it would be practicable...but it would be really good to get others thoughts and ideas on the matter.