Does not work like that. You will get poly meshes back from MoI which cannot be translated back into T-Splines.
T-Spline meshes will be translated into nurbs or poly meshes on the fly when you cut and paste into MoI.
On the way back from MoI you most likely will end up with Ply Meshes which cannot be translated into T-Splines again.
I fear that MoI is not adding any benefits to a Rhino - T-Splines combo.
Hope that helps...
Lemo

PS: I am giving a T-Splines/Rhino/Rhino Cam Webinar in July... If interested I post the details as we get closer here.