14.7:1 is ideal for burning the fuel efficiently but is dangerously lean under high load.
The AFR shown is max, I paused the video where you can still see the AFR graph. It starts around 14.7:1 then drops down out of sight, but it's below 13:1.
14.5 or so is fine for cruising. As long as afr drops at wot, you're okay.