This has not been my experience, unless everyone is in the same room. Pretty sure they only ship to one adddress per room, but they will ship to the address listed on each room if you have more than one room.
DO make sure everything is correct when you get your paperwork. If not, you can call.
I also know that ME needs, I think 24 hours notice (might be 48). Once we had to wait until we were at WDW to book the return ME. I think my sister was leaving before the end of our stay, and it was suggested to me that that was the best way to do it. I don't recall exactly, but we booked he arrival before we went, and her return trip once we were there.