No, and that is the promise the test suite measures on every run. Before two meshes are called copies the add-on compares vertex, edge, face and loop counts, the coordinates, the loop order, every UV channel with its coordinates, material slots, shape keys with their coordinates, custom normals and every mesh attribute — which is where smooth shading, material indices, creases, seams and colour attributes live. Four differences were planted in turn during testing: flat versus smooth shading, a changed material index, a moved shape key and a recoloured colour attribute. In each case it found zero groups, merged nothing, and the render came out unchanged.