MRC Thank you! That's a very detailed and candid answer from Vidal's designer.
Still, what's left unsaid is the actual up weight of their current design. It seems that acoustic like down weight - up weight spread is something the designer is keenly aware of and tried to replicate - a truly applaudable effort. Yet, the inability to do so satisfactorily may just show the inherent limitation of a simplified wooden action design. I read up more on the source of friction (which is really what the down weight up weight spread is about), and they are, in the order of decreasing amount: the knuckle, the hammer shank centerpin, whippen centerpin, key bushing, and the capstan. In simplified digital wooden action the source of friction is only from key bushing (Vidal, Kawai Grand Feel), and maybe capstan (Kawai Grand Feel).
It is so far my own opinion that Kawai Grand Feel and Vidal actions are fundamentally the same design. At $3k, Kawai Grand Feel in MP11SE is a mass produced action that has so-so quality control and regulation. At $6k, Vidal is meticulously crafted and regulated to give the best possible feel of this action design. Then, at > $10k, a huge jump in price and form factor, the hybrid action (Kawai NV10S/NV12, or Yamaha N1X/N3X), one gets an action that is essentially the same as acoustic action's design and feel.
There is, of course, nothing wrong with choosing any one of the above based on one's particular need. I just thought it would be helpful to get a thorough understanding of what one is paying for in each choice.