Ooo sounds like a bit of a breakthrough!
I'm sure Alfie mellowed with age.
If Sukei has a favourite treat then it's a good idea to throw that in his food bowl to reward him for going back in his cage nicely when asked. Might help encourage the good habit.
Alfie knows that he gets a pine nut for stepping up on the perch (or arm, if he so chooses) and he gets 3 or 4 in his food bowl once he's back in his cage. Has really helped cement the routine.