You must have
DCL transfers in order to do the luggage pick up at the Hyatt (or be charged for the luggage transfer). SO, you will tell DCL when you make the transfer reservations.
As for the Hyatt, you mention it on check in and they will give you an instruction sheet; basically it is luggage pick up at 8 am, whether or not you can do your cruise check in at MCO, and earliest time for the bus (departs at 9:30). IF DCL is doing the cruise check in at MCO, it is very easy; essentially no lines, and they do everything--security photos, boarding pass, etc. However, every member of your party must be present so they can do the security photo.