I run in to people unhappy with heat pump performance all of the time
I live in an area where a lot of people from northern states relocate to, and they are all used to oil or gas heat
my diagnosis in this case....
Yankee with a heat pump
sounds like he cant grasp the concept, Id set up the balance point the way you think it should be done, if you do it his way tell him its on his dime if he is unhappy and calls you back to change anything, then at least you will get paid for the headaches.