When you use ACN and summoned your pet, if you use Mouse configuration, the Pet Bar will appear; on Gamepad configuration, you switch/toggle to Pet Bar (Cross Hotbar) using R1. If you want to gain access to Cross Hotbar 1-8 while having a pet summoned, you will need to R1 (hold) 1-8.

I just started playing as ACN and I decided to use keyboard/mouse/gamepad combo by unchecking Enable Direct Chat. So 90% of my gaming is done through Gamepad and some spells and command are done through Keyboard and Mouse - which works quite well to my liking.