We live in south Florida and have driven the Lucid for two years. We have never found the car unable to keep the cabin comfortable after a cool-down period. We also drove the car on a trip to the Carolinas during the 2021 summer heat wave that saw 108º temperatures without any discomfort. Even sitting on black tarmac at Walmart charging stations we found the cabin tolerable if not quite crispy cool. I have also spent a few hot, sunny afternoons sitting in airport cell phone lots waiting for arrivals with the A/C keeping up just fine on the "auto" setting at 70º. (The glass roof in any car, including our Tesla, gets hot to the touch when there is no airflow over the glass. So there was a noticeable heat gradient as you neared the roof while sitting. However, the A/C kept up.)
Before delivery I looked into the feasibility of applying a tint film but dropped the idea after living with the car for a while.