I think the request for 30 minutes is a major tell, its gonna be intense pressure on old Joe to hold it together, physically and mentally.
At the sham primary debates, he was able to hide behind the other liar candidates and let them do all the talking.
Seniors can “leak” and with Joes issue might not be able to even identify the urge.
I believe you are right. If the Biden team were smarter and Biden himself could handle it , it would be a head fake.