A peculiar observation here...
Game: RUST at custom graphics settings with FPS limited to 60 at full HD on an external monitor
Same game same settings... only difference is connected to power vs on battery...
Game FPS fell from 60 on power to 30-45 on battery.
Predator Sense though shows higher CPU and GPU usage, albeit at significantly lower temperatures.
My power settings are common for both on my power plan and in ThrottleStop - only differences being:
1. EPP - 128 on power, 255 on battery
2. Turbo - enabled on power, disabled on battery

I thought maybe the EPP to 225 made a difference and made it back to 128 to be inline with power connected profile. Apparently that's not the driver for this.