It would be really handy to be able to rearrange material element order on skeletal/static meshes within the engine. We just ran into an issue where one of our characters didn’t match the order of the others (which messed up some connections we have setup) and everything we did in Maya to change the order wouldn’t work. We ended up having to import the fbx into 3DS Max and change the material IDs there, then reimport into the engine. Being able to just shift the material order in engine would save a TON of time in situations like this (even if they’re probably not very common).