while I was looking forward to this mouthpiece 2 years ago, I quickly understood that Aodyo was pursuing other priorities.
In addition, although Aodyo said at that time they were working on it, there was no promise to deliver it in the near future.
This being said, as sonsdanslair put it, the slider and the shake vibrato are very far from the original sensation of acting on the mouthpiece.
The Sylphyo is so great for its ability to let the player blow into it as it is with a real woodwind instrument that, people used to such acoustic instrument natural expect the mouthpiece to react the same way.
I used to play the clarinet. I never use the slider for effect. shake vibrato is quite effective and natural.
But I definitely miss a "smart" mouthpiece.
Look : I tried using a clarinet mouthpiece instead of the plastic mouthpiece of the Sylphyo. It fits very well and I can modulate the expression by biting the reed more or less as I would do with the real instrument. This brings some vibrato control.
The thing is that it is not like a real reed ! For instance, sometimes I surprise myself strengthening my bite on the mouthpiece when I want the sound of the synthetic instrument to be a few cents higher !
Understanding that Aodyo would not propose an electronic mouthpiece before long, I imagined the following DIY :
there are small ribbons (a few centimeters) sensitive to the pressure location and intensity,
glue this ribbon to the bottom of the plastic mouthpiece,
build an electronic circuit for mesuring location+intensity of the bite on the ribbon,
build an electronic circuit for converting to MIDI and transmitting this to a computer, wireless,
=> then you have a mouthpiece that can react to your bite intensity for some vibrato effect, or for pitch bending, and also bite location for changing the tone of the sound as it is on a clarinet or a saxophone.