Me too, two 27 inch 4k monitors, although thats with the MacBook itself closed. I tried running with the MacBook open for 3 monitors and it started drawing much more power and the fans revved up and became audible.
From looking at the threads this is a known issue running the internal and external monitors together can cause excessive power draw even with just one external monitor, something to do with mismatch refresh rate between the built in and external display and the Radeon GPU power management [1].
I also had kernel panics coming out of sleep with external monitors connected and window manager restarts although they seem to have gone away in the last Mac OS release or two [2].
Also MacOS still doesn't support display port MST so usb-c hubs with two display ports only can mirror not two independent monitors.
Overall pretty happy with latest 16 inch MacBook but MacOS has had more power management issues than I am used to, very surprising and annoying, with the usual non-acknowledgment from Apple of problems.
Same here. All the problems I had initially with my MBP 16" and external monitors are now completely gone.
The fan does come on sometimes when connected to a single 4K monitor (my 2016 MBP 13" never had that problem). I understand it's because of the discreet GPU kicking in. I really wish we could opt to use the integrated GPU with external monitors connected.
Other than that though, this laptop has been exceptional.
From looking at the threads this is a known issue running the internal and external monitors together can cause excessive power draw even with just one external monitor, something to do with mismatch refresh rate between the built in and external display and the Radeon GPU power management [1].
I also had kernel panics coming out of sleep with external monitors connected and window manager restarts although they seem to have gone away in the last Mac OS release or two [2].
Also MacOS still doesn't support display port MST so usb-c hubs with two display ports only can mirror not two independent monitors.
Overall pretty happy with latest 16 inch MacBook but MacOS has had more power management issues than I am used to, very surprising and annoying, with the usual non-acknowledgment from Apple of problems.
1. https://forums.macrumors.com/threads/16-is-hot-noisy-with-an...
2. https://forums.macrumors.com/threads/constant-kernel-panics-...