Smoothing groups from Max?

I have some rings and stuff like this that is 6 sides section and it would be ok to have it all smoothed while other walls with even more open angle should be faceted and I set them so in Max using smoothing groups.

But I see that Unity automatically creates smoothing groups at import. What if I would use my own custom smoothing groups instead? Is it possible?

On my Mac so I cant check right now but did you go over the FBX export when exporting it from max? I would think that it would be changed there.