I've used it- I have no concerns. Rocky just stands in his box every now and again. I just put it in his enclosure to make him feel close to nature because I am scared to put him on the grass, sidewalk, well....basically I shield him from the air (but I loop my arm around him just enough so he can get sun)!
Rocky ignore the box98% of the time. Be mindful because it could be a dusty situation at first until you figure out the balance.
I thought about it for Ruby but I want him to get a little older and he will probably throw it at me.
Good luck.