Interesting aspects and views shared in this thread now - have been away and not read in detail nor time right now, but like that there are so many who gives their input and share
However, I will say one thing, being an engineer working with design, analytics, and aerodynamics/design and a lot of flying - that for me when not trying to make something "new", I find joy in exploring how things works in real life, say windsurfing or hydrofoiling or whatever you do, and then make deductions and find the theory behind and how everything could or does interact, and share (or discuss).
And not the other way around - as if you have some idea beforehand of how things SHOULD work from other dynamic objects or even book studies or knowledge, you will most likely get this to work with what you experience out there, based on this often "pre"formed thesis, eventhough it is not really fully true in terms of what happens nor its significance, IMO.
To get back to the first post - I am still saying, that no matter if you use countersteering or kitepull or leaning over or combinations more likely, to start a turn, it is still the yaw input that is essential for a tight good hydrofoil turn.
It is all done in coordinated sync yes, also things like pushing the rear wing down in the carve, etc, we all agree on that I think, not in doubt.
It is IMO an incredible complicated sequence of motion and forces applied that makes a hydrofoil turn, and not just a single thing, of course.
A bit more precise, I could also say, that the skills we know from other, usually boardsports, are easy for us to implement without thinking, they are "natural".
The only thing that is really different for most or all of us, and makes such a huge impact on whether you succeed when learning to turn, is the twist or yaw input.
Later when learned to carve fully, one can even easier see how much yaw helps in terms of doing tight carves and not racing carves.
Maybe a few of us are born with the natural talent so we just "do it" without knowing we twist (good, as this is not how I nor most of those I know are), and this could very likely be why a few say they can not feel it (but be happy, you just do it without knowing)
I am, on purpose, not even discussing the theory behind what makes a foil turn - not necessary (eventhough another really interesting aspect indeed that we could talk about for infinite time yes) to deduct that yaw is such an essential part of hydrofoil turning
A few of you disagree or got their own thesis, it will always be like that.
I dont know everything either....
It is nice to read most have found the same and can reckognize the importance of yaw in tight carving turns, from themeselves
And to those of you learning to turn, TRY it, combined with all your othe natural skills, and see how you can suddenly carve much better and tighter when you get the hang of it