We took transfers from MCO and had to pick a PAT. When we checked in at the airport, no one asked us what our time was. We got there over an hour before our PAT and were able to get on the next available bus. I had called
DCL a month before our cruise and asked about picking a PAT when using MCO transfers. I was told their system is set up to make everyone pick a time, but that they don't care when you show up.