Upon opening, I have it blink a light in my office. That happens near instantly, in fact while “opening.” Upon being open more than 10 minutes after dark I get an alert, and I think that is quick. During the day I have an alert if left open when no one is home… that one is at the mercy of slower presence detection.
Edit: I will have to pay closer attention now as since 2022.11 my garage door was backed into by someone and I have MyQ offline because the opener is offline. Maybe my situation will also change due to the polling when I go back online.