UV2 blown out when calling ToMesh()

I am building a mesh via scripts:

var importer = new pb_MeshImporter(pb);
            var settings = pb_MeshImporter.Settings.Default;
           
            settings.quads = false;
            importer.Import(mesh, mats, settings);
            //pb.ToMesh(MeshTopology.Quads);

If I uncomment the last line then UV2 will get blown out and will be a copy of UV. I am uncertain what that line does in hindsight so maybe this is intentional behavior? I must have gotten it from an example and thought it was necessary to build the pb_object.

It seems like a bug to me but I wasn’t certain so I thought I’d post here first and see if anyone had insight on what that function does and whether or not it should be wiping out the UV2s.

ToMesh by design clears the UV2 channel. ProBuilder doesn’t currently have the ability to store user-set UV2 channels, they’re always generated by the Optimize function (available in Editor only).