You said..."I believe he has MBD because of the way he walks...
Kind of walks on his wrists rather than actual foot and waddles when he does walk which is very few steps"...MBD is a good possibility IMHO. I'm not a vet though so I can't be absolutely certain.
You said..."I've now got 5.0 UBV on him and dusted his foods, but is there anything else I can do to help him with the MBD etc???"....you can give him some liquid calcium gluconate. You can buy it at a pharmacy...but its quite syrupy so only give a little at a time with a dropper or needleless syringe.
If you take him to a vet, he can do tests to make sure that his problem is MBD and if it is he can be given a series of calcium injections followed after several weeks of these, by a shot of calcitonin. THIS MUST BE DONE BY A VET because the calcitonin will pull the calcium rapidly back into the bones...and if there is not enough calcium in the blood, the dragon will suffer from shock and likely die. I have been witness to this treatment of a series of calcium injections followed by the shot of calcitonin and was amazed at how well it worked...and how quickly too!
You may know the following information, but I will mention it just in case you don't. For good bone health its important to provide the right basking temperatures since this aids in the digestion of food and thus the absorption of nutrients. Phosphorous, calcium, D3/UVB, and vitamin A all play important roles....and must be in balance.
Insects have a poor calcium/phosphorous ratio so dusting the insects with a phosphorous-free calcium powder at most feedings is important. A vitamin powder can be used a couple of times a month too...one with a beta carotene source of vitamin A guarantees that the dragon can't overdose on vitamin A. Preformed sources of vitamin A can build up in the system and cause overdoses. Vitamin D3 is produced through exposure to direct sunlight or UVB (that does not pass through glass or plastic)...but because I use only UVB lights and my dragons get no direct sunlight, I dust with a calcium/D3 powder twice a month. Vitamin A is antagonistic to vitamin D3 so they need to be in a balance.
Gutloading your insects with a wide variety of greens, veggies, etc. can also help. Take note of any products other than greens and veggies that you use though, because they may contain phos., calcium, D3 or vitamin A...and that needs to be taken into consideration in the balance.
I feed my dragons a wide variety of greens (dandelion greens, collards, kale, endive, ROMAINE lettuce, mustard greens, etc.) and veggies (sweet red peppers, sweet potato, squash, zucchini, carrots, etc.) and a little fruit (apple, pear, melon, berries, etc.) as well as insects.
The last dragon I had die was over 11 years old...and I had him from about 4 weeks of age.
Good luck with the dragon!
