We only ever have used small cages for all our birds ensuring that they can stretch our their wings and the bar spacing are correct. However, our birds spend most of their time out of the cages and only ever go in over night and when we are out, which is usually once or twice a week. If our birds were to spend a majority of their time inside their cages, then we would have gone for bigger cages.
Parrots should at least spend an hour a day outside their cages for exercise ensuring that all doors and windows are secure to prevent escapees to the outside world