What to do with excess skinning knowledge 'tokens'?

So I’ve maxed out the skinning specialization and am getting close on Leatherworking. Why am I still getting knowledge points? Am I missing something?

you can trade them in for mettle at a vendor near the crafting order station in Valdrakken. As you’re a leatherworker also, I’d turn the mettle into insights and use them for either customer orders or if you’re not inclined to bark in trade, guaranteed r3 armor kits.

BRILLIANT! Thank you so much!