I have twice sailed on HALs Pinnacle class ships using CO . The first ship (KDAM) in Jan2022 I booked an aft Vista suite through a TA. I later to decided to Add CO to my cruise, After paying for CO they offered me an upgrade to a Neptune suite for $330 per person which was melded into cruise fare.( yes got spoiled) Understand cruising had been just resumed. I then went on to the Rotterdam TA in Oct but after the experience on KDam I called to add CO to the cruise. I enjoyed the perks so well I booked anther cruise on the NS while on the Rotterdam. I booked. with the advice of the on-board future cruise director, I booked the lowest vista cabin. After returning I had the TA add club orange and the moved me to the highest-class Vista suite . I paid $25 per day on 7-day Kdam and 15 per day on the other two which are both 15-day cruises. I had no waiting on first cruise but had up to 10 minuities on the Rdam. I enjoyed the early boarding and separate lines at cruise services as I am a minor mariner. You do have or have your TA call for the upgrade and pay for CO at that time
SSD.