Can you share how you're measuring GPU power draw? I have just migrated to a 16" MBP with the AMD chip, and also use an external display some of the time. Have noticed the fan noise and heat but it hasn't been a problem yet.
I use iStat Menus and look at the "Radeon High Side" sensor for GPU power draw under the Sensors menu icon.
Cool, thanks for that
I’d guess they measure total draw and compare against their baseline eg when they say the GPU draws 20W it’s 20W more than whatever the draw is when only using the internal display.