It seems like this would cut down on false positives. Is there a youtube on how to do it?

We use that all the time. The trigger event starts the process. If you use AI, BlueIris passes the image(s), captured by the trigger event, to AI for analysis. You tell AI what to look for and what model to use. If AI returns nothing found, BI will keep a cancelled alert event. Easiest to see in the Web Gui. I don't know of any Youtubes, never looked. There are many discussions on here about same, including screen shots.