Contractors....HVAC ductwork question

KK part of my reasoning was that it might be on the small side to begin with. We ran into that a lot, retrofitting older, especially heat pump installs. I remember one customer who went from a heat pump to gas / AC had replaced THREE compressors (total of FOUR) on a system about 20 years old!!!!!

Kinda makes ya wonder who that "service" man was!!!!