So this happened

[Dxw425]

I used Reptichips for a while and honestly, it holds humidity really well, too much actually but my snakes all seem to like aspen more. I went back to it as i've used to for years.

As for feeding, Caesar at that size was eating medium rats i believe. He was/is a garbage can though and eats anything. You can also try quail and chicks. Caesar LOVED quail. Now at around 7', he eats a jumbo rat or 2XL guinea pig every 10-14 days. He was eating every 3-7 days until he got to about a year old. During the baby times, he pushed like no tomorrow unless he was kept fed. Now he only pushes in the evening when he wakes up and wants attention. Then i have to slide a door open and stand there and pet him a while while he checks me out and hangs out lol. He is by far the most 'needy' snake i have haha. And here are their set ups. I just use aspen like i said and offer 2 jumbo RB hides in AP T25s. You can see Caesar in the top cage sleeping in his hide haha. Rosey is down on the bottom there looking out the front.

As far as your snakes liking aspen more, did having them on the bark reduce their activity or likeliness to be roaming? I know my boas and blood absolutely love the aspen which is why i use it, half the time they don't even bother with their hides because the feel secure enough just in the aspen shreds. Do you have any feeding pictures from when he was about 4 ft by any chance, to get a visual size comparison? Or even know about that the weights on your mediums were? It seems like theres sometimes some variability in what people consider certain sizes, i'm wondering if my rat supplier isnt off a bit because what he sells as mediums seem pretty dang big and i could'nt picture my tic getting one down.
Also im fairly familiar with your setups, they look great and i hope all my snakes would behave the way Caesar does haha