I had some free time today and was able to get a few more measurements. I started out with a new filter as the poster above mentioned his was dirty with only a few thousand miles on his odometer, and I was surprised to see how filthy mine was with just under 5K on the truck. Anyway, no difference with changing the filter. What did make a difference was clamping off my heater hose running to the heater core. I took a few videos for backup at the dealer, but I doubt that will make a difference.
With heater hose clamped and outside temp between 85-90 degrees
-At idle with max ac selected 48 degrees at drivers vent
-While driving with max ac selected 46 degrees at drivers vent
With heater hose not clamped and outside temp between 85-90 degrees
-At idle with max ac selected 55 degrees at drivers vent
-While driving with max ac selected 50-51 degrees at drivers vent
-At idle with recirc off and fan speed 5 selected 59 degrees at drivers vent
-At idle with recirc off and fan speed 7 selected 66 degrees at drivers vent (absolutely miserable trying to drive at this setting with the sun coming in)
So it looks like it's possible some 21's may still have the same issues as the 19-20s. Clamping off the heater hose did make a difference. I wouldn't say it was night and day, but definitely colder. For reference, I am just outside Philly and we have yet to have any real nasty hot humid days in the 90s. I used a digital cooking thermometer and double checked with my neghbors IR thermometer. Today is not too bad out, just hot in the sun. Again, my truck is a Granite Crystal 2021 crew cab built Jan 15. As of my last dealer vist, system is at correct pressure and no leaks, working to "spec".