I'm sorry, but I don't agree. Hand position determines your strike point on a key. You are thinking in terms of one note, but we all know that music is a series of notes (often very rapid) where the strike point is mostly a function of where your hand happens to be when you need that particular note. Nobody is able to place each individual finger higher or lower on the key surface depending on what you subsequently want to do with the note.

I rather like the idea of a sideways rocking to get finger vibrato, but again, how does the machine figure out what is your deliberate intent, and what is merely the motion of your finger going down and coming off with a sideways component? You already come across this problem if you set aftertouch sensitivity up high enough that you don't have to press very hard to activate it (so that even your pinky could use it, for instance), and now every single note gets a 'blip' of aftertouch data simply from the strike force of the key..! Make aftertouch do something other than the subtlest effect, and you have some nasty things happening.

I am VERY interested in getting the most control I possibly can from keyboard playing, and I've played just about everything out there that attempted to get better control. Other than LH controls, little has ever been of any use trying to get more emotion from simply one hand playing by itself. Aftertouch has been the most successful, and mono AT the only one practical enough and affordable. This doesn't strike me as either.

I am FAR more interested in alternative approaches to things you can do with your LH to ADD expression to the right, or with voice programming tricks (like SA2, SuperNatural, etc.) that analyzes your playing and substitutes the appropriate samples to better reflect what you played. I can honestly see far more use for something that figured out your note playing density, and adjusted vibrato speed based on that (slow passages are generally vibrato'd slower than quick ones by most players) or adjusted the delay of an LFO onset depending on tempo and note density (which is another common function) than something that I have to utterly change my RH (and LH!) technique to be able to use (if it WAS possible to change enough for it to be practical).

Then there's the question of your feet... Drummers, organists, pedal steel players, many types of instruments have discovered that there is a LOT of creative control lying below your knees! There's a ton of things you can do to enable good pitch control with foot controllers, a FAR simpler and cheaper (and already existent) system than this one!

TBH, you are looking at only one to two axes of control by moving your finger about on the key surface. And some VERY complicated adjustments to your technique to fully control it. Two footpedals would achieve the same degree of control, with FAR less adjustment to technique...

The idea is the RESULT, not the process. This touchphone key system looks like an utterly impractical and highly expensive way to do something you could do with one or two control pedals. Look, no-one is suggesting that you press a button on the bow of a violin to enable vibrato... something already exists that achieves it. But here we have some sort of Heath Robinson gimmick to do something that two pedals could do just as easily.

So, the question... Why?