We have a number of meshes that are quads in Maya. We export them as Quads to Unity, i.e. no triangulation on FBX export. Because of our app's special behaviour, we have some runtime calculations that we do based on the quad mesh. However, we then want to apply the results of those operations to a tri mesh (our targets include mobile, which can only render tri-meshes.) If we import a quad-containing mesh twice, once with "Keep Quads" and once without, does unity make any guarantees about the correspondence between the meshes such that we can generate a mapping table between faces of the quad-mesh and faces of the tri-mesh. Alternatively, we could write our own quad-ification algorithms and run them on the triangle meshes at runtime, but we'd way rather let the art team define the quads in maya.