Thank you for your reply dpb, I missed it when I posted a few minutes
ago, I lost a post somewhere, so if this one is a duplicate, my
apologies.

See, I think you could be right about the inspector. I'm sure he's
quite knowledgable, but if he's seen this problem often, I figure hvac
units are installed by certified hvac techs.. who would be more likely
to be the expert? Additionally, the lack of any liability for his
findings/report makes me hesitate to take his word as gospel... if
he's wrong & there's a problem w/the unit after we switch to 15amp,
who is liable? maybe me? I may end up telling the buyers if they
want me to have it changed, I'll have it changed, but I've let them
know I'm not certain it should be done. I'd contact the
manufacturer, but I'm afraid of voiding the warranty.

This is a new unit, installed a few months ago, installer seemed quite
competent and knowledgable.