Update: Big guy continues to improve and fatten up. He seems happy but still doesn't really like hands in his house. He seems to be somewhat used to me by now, but he likes to yell at my lady when she feeds him.
The only thing that has been somewhat tricky to control is that perfect humidity range. I can get the cage into the high 60s after a misting but it dries out after an hour or two. And stays around 55-60%.
That issue will be solved soon, as my friend very graciously offered to give me a fogger that she ordered too many of, to be used to supplement a healthy humidity level.
Overall, this guy is doing great now

I can't wait until his colors start coming out. I wonder how long that will be from now...