This is why I think it is comical people don't think the Kestrel works, for EVERYTHING.
How else do you calibrate your vision to an actual value ? You compare the readings on the kestrel to what you see around you, be it flags or other indicators. Then you have an actual VALUE to use...
A 1 MPH wind will move a 175gr SMK 10" at 1000 yards... there is no way to look at something 1000 yards away without calibrating your vision to a reading. Back in the day it was done with years and years of practice... people called it experience. Today we can use the wind meter to cut that experience in half.
Once you have a value, you can then use it to formulate a dope for that value. When you see the flag or mirage increase you can then tell yourself, "self", that is a 10MPH gust which means I need to hold, "X" or you can say, "self" that is an 8 MPH wind so I need "Y" ... instead of using bullshit generalities like 8 to 10, you know when it is 8 and when it is not.
Never in my life have I heard of a winning shooter "watching the other guys" if you are paying attention to them, you are not focused on you. Unless it is a team where everyone is in sync, even then, they usually have a coach who calls it, not each other looking down the line. I have shot F Class, I fail to see how you can expect to succeed watching another shooter when you are shooting. Sure observe the other relays when you are off the line... I would be glued to a scope if I felt the wind was acting unpredictable. However experience has taught me it is not nearly as unpredictable as you think. We just don't have a plan in place so it is nothing more than noodling.
40MPH winds on the first day of the SH Cup and still a handful of shooters shot better than 50% of the targets for the day. I bet they had a plan and knew what 40MPH meant in terms of their dope. Wind, drizzle, and terrain which moved that wind in wicked ways... and there was nothing but you on the line to observe when it came time to press the trigger. So clearly the better shooters were working the problem on their own.
Wind first Day
Finally, recording your data is key. Even with all the electronics I use, even image of still has my databook on the line. I record everything... here is the teaser for the most recent wind lesson, consider this teaser is 1/4 of the actual lesson.