You are correct about the time needed at the airport. That is not what the OP asked about though. We allowed 2 hours once we got on airport property Saturday. We did curb side check in, returned the car to Hertz, rode the shuttle back to the airport. Then through security, and we still had an hour and a half before flight departure.
I am glad that I allowed extra time just so we wouldn't feel rushed. Daughter had a box with lots of Disney pins for carry on and we were afraid we would be slowed down by TSA screening. They just looked in the box and we were on our way in a matter of minutes.