Why it matters on your quote
A correctly sized system can still underperform if the refrigerant charge is off or airflow is too low. ENERGY STAR's quality-installation guidance focuses on correct refrigerant charge, adequate airflow, matched components and sealed ducts, and equipment labels warn that not confirming charge and airflow may reduce efficiency and shorten equipment life.
Because these checks are invisible once the job is done, ask for them in the quote and for a copy of the readings afterwards.