This thread that was supposed to be about top of the line phono stages has temporarily morphed into a thread about amplifiers. . .
Of course I was aware of the so-called "weakness" of the Ypsilon Hyperions before I bought them. Importantly, the distortion that is graphed in your picture is linear, and only at very high frequency. Distortion in musical instruments is also rather linear, so the amplifier seems well designed for music. (Distortion in most solid state amplifiers, as I'm sure you're aware is dramatically geometric, and that's why solid state can sound so bad at the extremes.)
By your critique of transformers, it seems that you need to learn how transformers actually work.
I suppose a good summary of this last part of this discussion is that we don’t know as much as some people think that we know, and that includes engineers and doctors.