I have an overheating Macbook Pro (same goes for Macbook Air as well) and as far as I see the problem is caused by the Zwift application not providing the option to decrease CPU usage (i.e by frame rate?) in the game. Reducing resolution doesn’t solve this issue. There is an option for battery saving, which actually decreases frame rate on the backend afaik, but obviously applicable only when power is unplugged, thus if you work on battery, it works cooler and actually the fans stop. Else, fans blow at 100% and it feels like the notebook will explode any time Needless to say CPU temps go well over 100 degrees celsius. :o
Soo, this is clearly a Zwift for Mac optimization issue, and not being resolved so far is a big disappointment if you ask my opinion.
If I were able to run Zwift while the macbook is powered, I would be able to continue using clamshell mode but now I cannot. (When lid is closed, if you unplug the laptop, secondary monitor is disabled. You need to open the lid.) And when unplugged, with the current battery health, I can ride about 2 hrs max, and the battery dies.