As usual I'm with Okapi on this one, looks like we have the same kind of workflow. I often rebuild models from draft poly object, and for the moment I have to do printscreens in my poly software and use them as images reference in MoI.

I have tried the _meshtonurbs in rhino, but it's not that great on mid-res models (5000+ polys), MoI can handle it easily, but the wire curves slow down the viewport a lot on this kind of modelds. But maybe layers will allready help a lot, if it's possible to put the meshnurbs'reference one a layer and hide the curves for this layer.