That's awesome he loves the chop mix!
Careful about the amount of grains you have in the chop mix. Rosie is a bird who flies daily and is extremely lean, as well as eats good food. Yet when I took her to the vet they said her first fatty tumor was looking very fatty, and there is a second developing.
My avian vet told me to completly remove grains, exept corn, from Rosie's diet. They don't need all those calories and it can hurt them. Galahs can get fatty liver disease very young if they are eating wrong.
You'll want to be extra careful with Chilli since he's clipped, he can't get the vigorous exercise he needs. Do you have a gram scale? What I do daily is weigh Rosie and feel her breast for muscle mass and to check for any fat on a daily basis.