For a 6:30ish flight, you will be picked up between 3:15 and 3:45...depends on the resort and the route the bus will take. You will get exact times the day before you leave. So, with that in minid, I would plan on being back at POFQ by 2:45. The time you are given is the time the bus is supposed to be pulling away from the resort, so you need to be out, and ready to board, 15 mins prior to that time.
Most people like to make one last bathroom stop at the resort, check out the gift shop one last time and then get any carry on bags they may have left with Luggage Assistance. All that can take over 30 mins!!
If you leave MK by 1:30, you should be fine. Of course, if you've left plenty of time, that means the bus will arrive about 2 mins after you get there and go right to POFQ!!! But if you haven't left enough time, that's when everything will take longer....you will just miss the bus and have to wait 25 or so mins for the next one, there will be 2 scooters to load and then the bus will make two stops before your resort......just seems to work out that way! So, better safe than sorry.
With CP, I would ask for the check as soon as you sit down. Tell your server you are on a tight time limit....it can take awhile for the check to come if you wait until you're ready to go!!!!