I use copy for pet change,
I add all my chotbar 2 and make two set same as chotbar 2 on chotbar 7 & 8, on R2 XO buttons, i place all my Pet's abilities, so on 7 i put Eos, on 8 i put Selene, the others are identical.
With this i can easily summon my Pet and have my chotbar swap between 7 or 8 to be place on chotbar 2 with ease. ofcourse this way, you used up 2x chotbar which really to me is very inefficient.
