Why on earth does this thing count against your cap? This makes these basically worthless.
Why would you spend 90 Drake Crests (also a weekly capped material) to get 15 Wyrm crests when those 15 crests count against your cap??
I don’t understand the thinking here.
It’s for people who don’t need drake crests, but aren’t doing content that awards wyrm crests.
It’s not supposed to be bonus, beyond cap, wyrm crests.
You can only do this if you have no use for drake crests.
I have no use for Drake crests. However, I am doing content that already provides Wyrm crests.
So, exchanging my drake crests for something I am already capping on is worthless.
I don’t get why you would need to hit 472 in order to even be allowed to see this exchange and then it would still require you to exchange 90 of a capped material for 15 of a material you very likely already have.
That’s fine, it’s not really for you then. It’s for people who do like normal and LFR and world content.
Because if you started a new character / came back to the game a month or so down the line and your caps for drakes and wyrms were 300+ of each, and you outgeared drakes while you had maybe 150 or so left, but had still only gotten 200 wyrms, it’d help out that you could convert those 150 drakes.
Tldr the function is not there for you.
Can confirm. I used my first two weeks worth of wyrm crests and am effectively unable to upgrade any slots until I earn more this week. Since I will target dungeons that only drop aspect crests I would have to wait until I capped Aspect crests to start earning wyrms or run lower level content where the only benefit would be the crests.
Upgrading whelpling and drake means I need to do less content that drops wyrms and that the lower crests weren’t wasted effort.
I don’t think it really is for people that only do LFR and normal…
You need to reach 472 before you are even allowed to see this exchange at the vendor.
You need to reach 463 in every slot, what your average ilvl was when you achieved that isn’t what matters. The bands for achievements are 450, 463, and 476 respectively to outgrow each crest type.
ah you are right, I misread, it is 463. Still, seems pointless to spend 90 of a limited currency to get 15 of another limited currency against the cap.
Its pointless for us because we’re playing since day 1 and consistently capping. It’d be less pointless if you joined the game a month or two from now and finished with drake crests while you still had hundreds left.
Its also a nice, albeit slow, leg up for people wanting higher ilvl. You can convert your drakes into wyrms and then use them to craft 476s.
So it’s purpose is more-or-less exclusively as a catchup mechanic for people 1+ month from now? 
Kinda, yeah. let me put it another way.
Would you rather it been not part of the cap, thereby incentivising players to never spend drake crests prior to earning 463 in all slots, lest they miss out on extra free wyrms?
The current design is saving you from yourselves.