Hey!
Just to cover some things, beardies do not need hides, im not sure if thats what youre using it for or if its for something else.
Secondly, what kind of uvb light do you have?
Mealies are a huge No no for beardies, you can try super worms when he is a little bit older. Right now he should be eating between 30-70 vit or calcium dusted crickets and get misted a few times a day. They do not need calcium dishes, they get their calcium from the dust you put on their crickets.
4.5 inches at a few months old is small, but I know he was not in your care for a long time. hopefully with the right husbandry he will start to grow for you
Feel free to ask any more questions! - Matt