I've read all the arguments for keeping hatchlings in a closed chamber. I either can't find and/or can't remember at how old it is ok to move them into a less humid enclosure?
I remember once reading @Tom's response to this question and it was "as long as they are growing, they need high humidity."
Although this made complete sense, I got worried that I would have to dedicate an entire bedroom to a tortoise until it fully grew.
Now I realize that they can be moved outside earlier and a humid hide is sufficient.
You've got the idea.
This is very climate dependent too. Its really really dry where I am, so I have a difficult time keeping the growth looking smooth and nice the more time they spend outside. In a more humid area, this transition would be much smoother, and so would the growth.