I make a test today: Put Filter-Oil from K&N on a cotton cloth (K&N filters are make from cotton) and take a light on it. It burns. I don`t want say that this is a evidence that the chance that a K&N filter burns is the same that from uniflow. But I also can`t except that and it was remarkable coincidence that the uniflow filter of this motorbike on the picture burns.
But probably I`ll buy K&N, because I think it is better to pay a few money more than the bike burns.