I don't think one could / should go only by weight when making the decision to house an animal in a different size enclosure. Some don't seem bothered by a larger than they "need" tub, while others are / might be. It really comes down to the individual animal for me. In my mind, it's also a pretty significant jump from a 16 to a 41 quart. I typically use a 28 quart / sweater box size as an in between.

Like Sonja said it just depends. I have had hatchlings that went straight into a 41 and never had a problem and had a couple fully grown males that just never did well in anything bigger than a 28. So there are no set of rules just play around with it and see what works.

I just moved my Banana.  She was well over two feet, and that was the length of her old house.  So I put her in her forever home of 3x2.  No stress, still whomped down a mouse for me.

I start my hatchlings in tubs about 1/2 the size of a 6qt - very snug but they usually start feeding more quickly in my experience than if they were started in 6qts. After they eat a couple times and shed I transfer them to 6qts. Hatchling to around 300 grams seems appropriate to me for a 6qt tub, but by then it is definitely time to move up to a 15-16qt tub.

I believe 250-600 grams is max weight for for 15-16qt tubs. Once they get to 600 I move mine into 28-32 qt tubs. My males are all kept in 28-32qt tubs since they are all under 1,500g. They are perfectly content and most eat throughout breeding season steadily, so it seems to work well.

Females are given 41qt tubs once they reach 1000g. Smallest I would personally put in a 41qt would be around 800 grams. Not saying smaller can't do well, just my preference and what has worked for me. It really depends on the animal, some like to be cramped and won't eat otherwise while others definitely need more space!