Looking good. However with these guys I'd reduce the water area. In my experience they can be a pain to acclimate, for every one that lives, at least five die. Get lots of house geckos and green treefrogs in there to feed them. Then just leave him alone for several weeks until he is nice and fat. Then treat for paarasites. Stress will kill vine snakes overnight!
This specimen I've had for 4 years now. I've found that if you get a healthy specimen they are a very hardy animal. It has thrived in humidity ranging from ambient room ~20-30% to 100% and temps from 70-90F.
The main issue is, as you stated, they have a very high mortality rate but this is (in my experience) not been due to stressing them out but the very very poor conditions they were kept in prior to purchase. I had three others prior to this one, 2 died in less than 2 days due to mouth/respiratory infections they came with. And the third one was doing awesome for about a year until it ate an anole I bought at Petco. Never again. Now I collect all my feeders by hand from my greenhouse. I purchased a large number of native Anoles from Florida and released them into my greenhouses and have been catching/feeding them ever since. This way I can control the quality of the feeders. I wish I could get a captive bred specimen, but I've never seen one available.
The water volume is irrelevant as it spends 100% of its time in the vines and plants. I've never seen it on the ground in any of the three previous builds. Also I've heard that they'll eat fish, but I'll have to see that to believe it.
For all my arborial snake builds I like to have large water bodies below the primary vine areas that way the feces can fall into the water and the misting system can help solubolize any extra and keep the tank cleaner. The canister filter I've got running on it is meant for a 50+ gallon tank and there is about 8 gallons total, so the turnover rate is quite high. That and making water changes is as simple as flipping a switch, all outside the tank. Keeps the mess down considerably.
This specimen was in this design for about a year.
Then I got tired of that one and rebuilt it into this one. Terrible picture, sorry.
Then I made this one and sold the old design. Even worse picture.
This design just plain sucks in comparison to the quality of my work now, so I decided to rebuild my paludarium into a cage to house it. The other half of the reasoning was the infernal cats that share my living space had taken to using the paludarium as their personal litter box. Which while really funny for everyone else, yielded a rather large mess and smell that I got to deal with. Plus they trampled/ate a number of the plants.
The bottom half, originally a paludarium, was a very basic design. I took the top trim off a short squat aquarium I had. Then using the foam replica rocks that I make from molds, I pieced together a retaining wall and used concrete/grout mixture inbetween them. I don't like to use that method anymore. Now I use something I've developed and is MUCH better to use and am currently manufacturing a custom formulation for use in this hobby. But more on that at a later time.
Then I filled the back area with LECA, pond soil, and gravel ontop. It looked like this.
I had built an acrylic top that dropped ontop of what was left of the original design. Then I used my replica rocks with "great stuff" to hold them together and give texture to the background. I then covered the foam in my custom material and covered that in sphagnum peat moss to give it the dirt texture/look I wanted. Very easy design and much easier to do than using silicone and works infinitely better than kitty litter backgrounds. It has the ease of use like clay backgrounds, but has the durability and ingredient consistency one would expect from a zoo quality material.
Then planted it, plugged in the misting system. Misting system built by using an Aquatech 6800 pump, standard Orbit's 1/4" drip irrigation tubing, and Orbit's Flex-Mist misting heads. The misting heads are low pressure so the water volume output is quite high, but as I want this to help clean the cage and water the plants rather than raise humidity, this is fine.
Lighting is a standard track lighting fixture with 7 lights. 2 27watt 3500K on right and left extremes, 2 27watt 5000K, 2 27watt 6500K, and 1 27watt 10.0 UVB bulb in the middle.
I am not ready to take on large numbers of rock orders for various reasons, but I can do small scale batches for people who PM at this point. I'm waiting for the manufacturing of my new products to finish before I launch the online store. But if you are interested in the rocks, send me a PM and I can make some for you. Prices are very reasonable. An example this rock design is ~$20usd. You can see the detail and color is still there well after a year of being partially submerged in the paludarium.