I got to level 86.5 on my Blacksmith by questing (no attempt to farm motes) and got 6 motes during it. So thought I'd try for 10 to buy a recipe. Just now I went out specifically to farm motes. I got nowhere in the Valley in about 45 min so went back to Jade where the mobs were faster to kill. Got 1 mote in 3 minutes, then nothing in next 45.
I'm not expecting anything, it's probably just random, but if anyone has noticed a pattern, thanks.