Ok so you have great lighting going --- the basking decor should be 6-8 inches from his UVB -- and he is eating --- from what you described I thought he wasnt eating at all --

ok so him not eating vegies is completely normal and w/ that being said this is what we need to do to get him to start eating those veggies -- your dubias are going to work great -- but we need to get him some things to entice him to that bowl -- you need a glass or ceramic bowl so the worms cant get out of -- you can order some BSFL or calci worms or phonenix worms or nutri grubs they are all the same worm -- you can go here and shop
www.dubiaroaches.com from here you can get some of the nutri grubs and some horn worms -- order the horn worms medium and only order small amounts they grow really fast - we are going to use those and the grubs to lure him to the salad bowl - the silk worms are a great staple feeder and can be used to lure him to the salad bowl -- use as many nutri grubs as you want order large they are small dont dust them -- the grubs are also a great staple feeder - so add 1-2 horn worms and the nutri grubs to his salad in front on him so he sees you do this -- the movement will get him to the bowl --- you want him eating some of that salad -- do this every morning -- I would let him eat from his bowl for like an hr before feeding him his staple feeder the dubias they can be added to the bowl as well - take a little of the salad out be leave some in and let him see you put those roaches in the bowl - that will get him back to the bowl -- I also recommend butter worms which everyone is out of now I cant find them -- and some super worms but I dont know how big your guy is so I would say around 3 months old get him some super worms medium and start adding those to his salads too 1-3 -- worms will entice them to the bowl and hopefully start getting him to eat his salads - the silk worms as well --
here is a website for nutrition ignore the kale thing its a good staple feeder
http://www.beautifuldragons.com/Nutrition.htmlI am going to give you some websites for other worms etc
www.reptilianarts.com they have good silk worms - if you order in bulk like 50 make sure you get food too you will need to feed them and clean containers out daily -- they come small
www.coastilsilkworms.com www.mulberryfarms.com they are spendy on shipping
www.symptonbsf.com good BSFL
Hopefully this will help --- he can go into his new tank anytime -- the T 5 should be used for your new tank and not the 20 gallon --- its going to be too strong so keep your T 8 - it can be used for a back or for another tank at some point --
Happy shopping
Karrie