I put 7,500 miles on my ‘19 CVO SG with a 131, most of them between May and August of 2020 in the NC heat. While I did notice it being a little hotter than stock I did not feel it affected me to the point I could not enjoy the ride. I ran the FM 2/1/2 Jackpot header, MK-45 mufflers and the H-D auto-tuner.
I did have the H-D cool-flow fan installed and the bike was oil cooled, so I had the H-D recommended fan assisted oil cooler on the bike.
I never had the bike on a dyno because I didn’t think there would be enough adjustments that could be made to accommodate the cat-free header. If your bike is running so hot you can’t enjoy it, I agree with others it could be an issue with the tune. The H-D tuner cannot tune for an exhaust without a cat. If you want to keep the warranty as long as possible try the cool-flow fan, maybe that will help. Good Luck...