Admittedly, I could never see myself clapping for Biden or Harris.
I would, but only out of the respect for the office, and not the man (or woman) and only in the most perfunctory way. It's basic civil etiquette in America. Same thing in military (you salute the rank, not the person) or when we stand up when the judge enters the courtroom.
After that, of course, I wouldn't applaud anything they had to say.