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.”