I don't really understand this either. I mean, I get that keeping it locked to a higher level gives you something to look forward to as you level up, but I feel that something as trivial as overwriting the appearance of your gear being locked behind the 2.x level cap is a bit strange. If I recall correctly, we unlock dyes at 15 (?), so I don't see the problem with making glamours available at that level or maybe lowering it to 30. If anything, giving players the ability to customize their looks at an earlier stage may motivate them even more to progress through the stories/levels in order to see what else is available for glamouring. With that being said, unless there's a very important reason for locking glamours to level 50 like it being tied to the story or something like that, I don't see the harm in relaxing the condition for unlocking it just a tad bit.
