doing a snapshot should be the same as a xform reset, so it should not matter if the mesh has been mirrored correct?
I think that when you make an snapshot or a xform reset, all the mesh vertices are transformed by the node’s current transform matrix and (in the case of a xform reset) then this matrix is reset to the identity matrix. And because of this, when you do a mirror the object is scaled negatively and then, when vertices are transformed, the faces and normals are reversed. I’ve done a test and seems to work like that.
So doing the handedness check, you can take care of this situation. I do that in the exporter I did for our 3D engine and always worked properly. The good think about this is that you don’t need to care about mirrored objects.
Anyway you can skip the check and try for yourself.
Greets.