Since Blizzard will probably never remove the crest cap, why not make another system of it ?
So, lets say you earned max gilded crests from m10s, why instead of giving you nothing when you capped all weekly crests, they convert to a warbound token for lets say…
25-50% of their original value you would have gotten from the key.
And to not click one and one you could have an exchange vendor like the anniversary event, to convert the bronze tokens into timewarped badges.
Just an idea.