Would it be possible to convert poly groups to geometry masks in Subatnce 3D Painter?

Hello all,

I just started learning how to use Substance 3D Painter.

I understand that I can create geometry masks in 3D software like Maya, Blender, MODO, etc. by separating the mesh parts. I have a model from a CAD program that has vertex normals so I don't want to split polygons that may break the normals. I can assign parts to polygons in my case in MODO or poly groups in ZBRUSH, etc. They are interchangeable between most 3D software when I export them to OBJ or FBX. But I noticed that Painter doesn't recognize them as geometry masks unless I sprit the meshes. I may as well bake ID maps instead of using geometry masks so far. It could be handy Painter can read poly groups as geometry masks. Am I missing out on something? Any help will be much appreciated. Thank you.