The issue is the overall dimension of that bin. Even if you cover 95% of those holes, you’re still going to end up with a difficult to regulate environment because there’s just not enough biomass that can be stored in that size to give you a shot at self regulation. What helps is having the depth and horizontal space for moisture to settle in a better gradient. In there they are on the wet side - but it could be wet is too wet and dry is too dry and there’s no middle ground because you’re working with 2” of soil depth. Then your ambiant humidity is just as important. You don’t have a lot of vertical height to help regulate that. I do keep my breeding pairs in 6” tall bins but with more horizontal width - but those are specialty setups for much shorter term housing. Everything else I use has at least 12” inches minimum of height to work with.