Hello,

Maybe some sort of post-process micro beveling that works at the mesh level could work better than a full auto nurbs fillet idea. (might be part of the mesher ?)
I kinda like the rounded edges at render time, it works very well for stills or normal map baking, and I never had problems with it in Modo and Clarisse.

However, people seems to extract normal maps using SubstanceDesigner now, and last time I checked, there wasn't any round shader available for the baking (but there are so post trick possible once the normal is extracted).
I end up to create a little process in Houdini, that 'voxelize' / decimate / export Moi models, the result was super crisp.

Talking about hard surfacing, this video get lot's a attention lately from non CAD users ^^

https://www.youtube.com/watch?v=ctI-tMc8U7M

Spaceclaim for gun concept :
https://www.artstation.com/artwork/3DJdB