I have “purchased” ( miles, not $$) single-visit FL passes several times in DFW and ORD. I haven’t encountered any issues with the agents not knowing about it, but twice at ORD I ran into issues actually completing the transaction. One time they were limiting day passes and the agent thought that also applied to the FL single visit pass; she called someone to check and then it was ok. The other case was more frustrating; none of the entry agents could get the transaction to complete, they then sent me to the Admirals club to talk to one of the AAngels and they couldn’t get it to work either, finally they just walked me down to the FL on the 2nd floor. But we weren’t done yet; a little while later I had NINE 15000 mile deductions in my account, I guess from all the attempts. EXP desk cleared it up but definitely a bad IT day.