I did go through the same situation you have already, and DJ had to stay more time in his cage lately. I was worried just as much as you are, but then i noticed that DJ has accepted his limited time outside the cage. What i did was simple and it all depends on the amount of love you give your birds when you let them out. As soon as i come home and before i change my clothes, i go to his cage and tell him HELLO BABY. DJ gets so excited immediately, all fluffy and full of energy, step up on my hand and i give him a hug for a minute or two. The same thing with Susu too. Then i go to the kitchen and prepare a double treat for both of them. My maid keeps telling me how excited they both get as soon as i arrive home
I then move to my room and change my clothes, but i keep calling them the whole time and they respond saying (Hello and I love you). Then spend an hour or two playing with them along with my daughter. I can tell you they have not changed their behavior at all, they are still the same lovely parrots i know. From spending most of the day out of their cages, to spending 3 to 4 hours a day only! So i guess it's not the amount of time they spend outside their cages that makes them happy, but maybe the amount of love and attention they get. I hope this will help, and this is my own experience only.