he does make the important observation that it's more about your embouchure than just a set of fingerings. When the wavelength gets shorter than the gap between the toneholes, then fingerings will be of limited use anyway. Shaping your embouchure as if you were trying to sing the note you're aiming for and adjusting tongue position, lip pressure and airflow will help a lot.
I never got anywhere with the standard fingerings and devised my own method, based on dividing the air column by 2, 3 and 4 and opening an appropriate key at the right point to create a node.
There's a similar approach here -
http://www.bobrk.com/saxfaq/2.5.html
"Now... let's talk about creating your own fingerings. Look closely at the fingerings you use and figure out what they are doing. Essentially they are creating a new octave overblown at a harmonic rather than the octave. They enable you to use that overblown harmonic with your key system for a span of a few steps at a time before having to overblow at the next harmonic and start the key fingerings over. One key generally acts as a vent (an octave key) to force the harmonic to sound, while the other keys give you some fingerings that connect chromatically. The best altissimo notes are those overblown at the lower harmonics. They will be firm and have tone, not just squeaky sounds. The higher harmonics are absent in lower overtones, and therefore have less body to distinguish them from the same note on a flute or clarinet (or reed squeak). So, with this knowledge in mind, you can make up your own altissimo fingerings so that you can connect chromatic fingerings and have true usage of your scales and arpeggios up there without jumping from one key system (at one harmonic) to another key system (at the another harmonic). Am I making sense to you? I never tried to put that into words before, but have used it for decades in creating my own fingerings. Most people have trouble with altissimo not because it's hard to produce, but because the fingerings are so awkward.And they ARE awkward when you are jumping from one harmonic to another with each note. Keep them connected under the same harmonic and you will have virtuosic control."
the mouthpiece exercises are also worthwhile -
http://www.bobrk.com/saxfaq/2.6.html