The only concern I think would be how it adheres to other materials like metal? It may only stick to it's self best. I would also wonder about the thickness of it when applied in layers to fill an area. Are the fibers going to be hanging loose at the edge of each layer after feathering it smooth? I guess it would have to be played with a bit to find out because basically it is just fiberglass cloth strips and would be worked the same way.
If I disappear from a discussion please forgive me. My 24-7 business requires me to split mid-sentence to serve them. I am not ducking out, I will be back later to catch up.