I have a couple of suggestions, but you are off to a great start!!
His supplement schedule should be everyday dusting with calcium without d3 , twice a month with calcium with d3 and twice a month with a multivitamin. The feeders do not need to look like ghosts just a light dusting. Also gut loading your crickets with dark leafy greens is important too. Some suggestions are collard greens, dandelion greens, mustard, endive. Also sweet potatoes, carrots, etc. there is a list on here just search gut loads, there are also ideas for dry gut loads as well. Also variety in feeder as well, dubia raoches, superworms, silkworms, hornworms, they love variety!
Also I would switch his UVB bulb to a linear tube, I use reptisun T5 HO(high output) 5.0, it gives him more UVB all over the enclosure instead of focused on one area.The t5 bulbs only need to be replaced once a year vs. 6 months with the others.
Careful with the substrate on the bottom too, if you are free roaming his food as it can cause impaction.
To answer the original question about drying out to fast, you may need to cover a couple of sides with a shower curtain to maintain humidity. Real plants are also a huge help in keeping the humidity up and water stays on real plant leaves much longer than fake. I use Pothos they grow fast and are easy to keep, make sure you wash all plant leaves before putting them in the enclosure.
He is a pretty guy, I love veileds
