First off, please dont think Im "ordering" you to do anything, or "looking down" on your husbandry.
Do research, and do what YOU think works. We are all "learning" here.
I put my guy in a 3x3x5 at 3months, and free-ranged at 4 months.
I can tell you Im 100% sure hed be healthier and happier if you put him in the reptibreeze. I would do that tomarrow