well if you are comparing your leo's poop to what your beardie does, you're talking tiny. it is good that is was dry though--runny feces is definitely not a good thing.

can he see the mealworms in the dish easily? is it possible he can't see them if the dish has high sides?

keep trying the turkey babyfood with mashed mealworms. he won't love the fact that you are putting it on his nose and putting a spoon up to his face but he doesn't realize it's food that you are giving him. usually once they figure that out they will at least lick some out of the spoon. you have to keep the spoon right there so as soon as they lick their nose you can hold it so that they are licking from the spoon. sometimes this results in them jumping back or shaking their head because they didn't expect it but try again and they won't be as surprised by it.

how long has it been exactly since he has eaten?