Just so you know, B2B is very easy....all B2B passengers will be asked to meet at a certain time in a dining room, or lounge/theatre. When all leaving passengers are off the ship, you will be escorted off the ship to go thru US immigration, and then escorted back on the ship before newly arriving passengers. If you have to change cabins, crew will assist you doing that.
You will be detailed instructions a few days before arriving in the USA