Yeah i am definitely with you on this one, there is a massive lack of advanced thread,refine in events, therefore anyone who is done with medium is in a predicament, no one wants to buy them directly from the shop and if they do, it's a huge waste of potential value.

They should consider adding these to events more often, it's been a year now and we have barely seen any advanced refines in events just recently, but i can not even think of any events with advanced thread as a redeemable reward.