Disclaimer: I’ve performed the tests only on MacBook Pro 15" 2015 with macOS 10.15.4. I turned off all excess bluetooth devices during the tests. The trackpads were half charged. The trackpad settings were default except for silent and light clicking. I’ve checked that the external monitor gives zero delay compared to the built-in display. Please share your results if you have a different equipment. The results may differ on other hardware and software.