Concerning A330,itīs the most stupid thing to do.
You are just stressing one pack to work hard to keep the air at 22 degrees to fill the balloom. No change at all in the APU EGT.
But if you want to destroy the pack keep doing it. Itīs stupid rule made by idiots who sit in a desk and don't look out.
In my opinion using flap 3 for landing together with rev idle itīs another stupid thing concerning safety and the brake wear when you are close to MLW either on the -200 or -300. The company i used to work loves to do stupid idiot rules for us to follow. Another one is to taxi a widebody with only on engine runing.
They are the same that order boeing to install a brake fan for the B777-300ER,can u imagine that?For sure they receive a no no answer from boeing because it will cost a lot of millions to change the whole f. thing.