, I screened mne in and it looks great but I have a hard time keeping it closed, the screen is in the way. Maybe I will get up off my lazy ...and take a pic for you...maybe not :lol: 
Unfortunately it's often not that easy in captivity since you might not have the right incline, height, branch surface, etc. If that cage remains the same you'll find out.
Well the surface area of the lid is far greater than the little twigs you have in there. The twigs also seem kind of thin to me, especially when they are sharing the cage with other mantises and must practically walk on top of their neighbor if they should try to pass each other on the twig. I have to admit though I don't have any experience with mantises molting on sticks. I use all screen cages and have yet to have a single mantis choose to shed on any of the many sticks/other cage decorations I provide. They all prefer to use the screen and I've never once had a mismolt so I'm not going to tell them their choice is wrong.The biggest worry I would have with your tank is the constants slipping and falling of mantises trying desperately to crawl up the sides and cling to the ceiling of the tank. Mantises seem driven to climb upward and no matter how many times they fall or how bad the grip is they will keep trying to climb up in that tank. Sure, in the wild they would cling to twigs, but in the wild they would also not find plastic completely encasing them only a foot off the ground.
Why don't you just separate the two newly molted and that way you won't have to "watch them often." aggression will set in and I have seen them attack each other even when there was more than enough food for them all. As they grow some tend to attack others more often than others! Trust me my nephew and I have spend totals of hours just studying their habits from nymph to adult!!! (too much time on our hands back then!!!) :blink: Better safe than sorry,mate, especially if you only have a small number of mantids. When there are large amounts of course as I have learned from the members here, you can decide how much cannibalism to allow just to ease back on the numbers, if necessary!
The branches, dinosaurs, (compliments of my then 7 yr. old), a few silk vines and what not, provided cover so that the mantids would not just be in eye contact all of the time planning their next attack!!!! h34r: So, I ran out side, in the deep of winter, and grabbed up a few branches to put in and this helped tremendously!! They molted from the branches as well as the lid, it just varies I imagine!Keep the oatmeal in the cricket container and try not to transfer any over because it will mold as you know. Problem is is that mantids seem to always want to get to the top and in this case that is the lid which is slippery. I think all you have to do is add some holes for ventilation and glue a piece of fiberglass screen to the "top".I ran into a problem with mold. When I dumped in some crickets a small amount of oatmeal/cricket food went in with them. This apparently started to mold and spread to the buds on the branches I put in there.I have transferred the mantis into individual containers while I clear the container. I think it was the level of humidity in there. I never did get around to putting holes in the side to allow cross ventilation, so it is my fault.
As far as them having a place to hang to molt .. as long as they can hang upside down, how is it different than them hanging from the lid ?. The branches are real wood, so it is not like slippery plastic.
I thought I would mention the problem I had as I feel this is a place to discuss housing options and if none of us mention failures others may make the same mistake.
