To clarify, there are NO pharmacies here in Central FL that are issuing the vaccine, despite all the hoola about Publix being a distributer. It's only hospitals and health depts. And other temp sites. So, no waiting list.
That being said, I would suggest that all of the online appointment systems offer the online waiting list as well, much like Rise of the Resistance. Schedule extra people for the last appt of the day, but don't guarantee it. That way, if there is an abundance of doses that need to be used, they can go to those who have legitimately signed up and are prepared to arrive.