I agree that not providing proper humidity all the time will probably result in a poor shed. But I don't think you know for a fact that there isn't a window that is more advantageous to the shed cycle to provide humidity. And that's all I was trying to do here -- start a discussion.
I would argue, based off nothing but ignorant reasoning, that the animal would utilize humidity more so during the period the snake goes blue. My only reasoning for this is that they go blue because of a fluid build up under their old skin, which would make me think that this fluid build up would better separate the old skin from the new with more humidity. More moisture, I imagine, would aid the role of the fluid.
But that's my very uneducated guess.