There used to be a trackpad gestures app called Jitouch. And the Drawing activation feature was much better implemented there. You didn't have to activate gestures separately in any way; you could simply start drawing something with slightly spread fingers. It was truly fantastic. I would be happy if you could introduce something similar here, at least as an alternative.
If you want to see how it was implemented, you can check it out on GitHub. There's a talented individual who managed to revive this program, and it works quite successfully even on new laptops. But I would like to have such a feature in your program so that everything is integrated into one.