I'm going back more than ten years in my memory on this. I do not recall America West owning 321's. I never saw them in ORD anyways. US Air had a bunch of them. We got one every night.
When they merged they all got the US Airways paint scheme. I came in right after the Merger as a 'West' guy. The mechanics agreed on a merger/unification plan right after I got there, but the pilots stayed separate until long after I left. In fact I understand that still wasn't settled when they all rolled in to American.
The big way to tell if it was a 'West' or 'East' bus was V2500 or CFM. V2500's are smooth throughout the length of the engine, CFM's have a very visible break at the rear of the fan. The NEO's which are all CFM's have the scalloping at the aft edge of the fan. This is for those following along, not you
@TacticalDillhole
Anyhow, the button you speak of was supposed to give 33K thrust. As needed, you don't fly it that way all day. It wasn't emergency power, just extra to get you up to where you wanted to be. The engine was rated at that power, but derated to normally needed operational power. I never had to deal with any fallout from it or anything. Just one of the things you learn in GenFam that you never use.