I wonder what would happen if you were wearing sunglasses. I wear them regularly and almost never see the message. I did test it by intentionally looking down at my phone as if I was texting and it caught me so... ymmv.
Turning off autopilot to take your attention away from the road sounds just dangerous (not saying it's not necessary in your case).
While driving today, I decided to test this out. I do most of my driving during the day and almost always wear sunglasses. I've rarely seen the "Please pay attention" warning, but felt like it was more about which way my head was facing, rather than eye position.
So, with my polarized sunglasses on, if I looked left, right, up, or down for an extended period (more than 8 seconds) but kept my face forward and chin up, it never "caught" me. I was still being as attentive and safe as possible, using my peripheral vision and was on a stretch of road with no other cars around. Then, when I turned my head left, right, up, or down but kept my eyes facing forward, staring directly at the road, I got the "Please pay attention" warning. This suggests to me that it can't see through the polarized lenses and just relies on head position.
However, I also tested without sunglasses on, and if I was looking away, but had my head facing forward and chin up, it
did "catch" me. So, I guess it uses eyes when it can, but falls back onto head position if it can't see your eyes. I think that's about as good as they can do. If it yelled at me for wearing sunglasses, I wouldn't be able to use it.