Yup, I agree with what you say, Katia.
Ken, I don’t think you are being a curmudgeon. It seems that you have elaborated (usefully! 🙂 ) on several things I said above.
To quote myself,
“If it gets really high you can fix it by pulling the top joint out from the center barrel some.
So, if this is sounding like a moving target that is constantly changing, that’s because it is. Playing in tune on the recorder is a constant struggle and something players playing with others have to pay close attention to every moment, adjusting their breath pressure to get everything sounding good.”