From Moi to Nvil and back how to stay accurate

Hello
I have a project going on in Moi3d.
I want to bring some object into Nvil to make a "shell" around the object and send back to Moi3d.
What is the best format to do this and to import it and back and stay accurate?

Thank you!

Set MoI preferences to metres
Export from Moi in obj format.
Set NVil to metres in preferences.
Import obj into NVil using merge scene.

NOTE: Moi is a nurbs modeler (nurb surfaces). Nvil is a mesh modeler (Polygons).

MoI does not support import of mesh data that NVil generates however you can use the SubD function of MoI v4  to import obj format but it will apply a subdvision to the mesh geometry converting it from polygons to nurbs surfaces.

Thank you!