I have followed Carl Pullein for sometime. He is an avid Todoist user who started very strongly in the GTD camp and has evolved over the past couple of years as he has experimented with alternate approaches. I don’t always agree with the paths he takes but I always learn something more about my own challenges by listening to his YouTube channel and listening to what he has to say.
I hadn’t thought about Time Sectoring in regards to Agenda, but I agree, it’s an interesting approach.