I have now stayed on an AP rate 3 times. Not once have I been asked to show my AP at check-in. If I call to make a change or adjustment, I always get the spiel that I will need to, but it has not happened.
I was even texted a room ready text that could have allowed me to skip the desk (my bands never work so I always have to go to concierge) completely on an AP rate.
To be safe, I would make sure you were present if you needed to, but I figured I would share my past experiences.