From what I have read so far, I think you are all talking about the same thing, in that most manufactures have 2 sensors on there keyboards, one measures the speed the key is hit, which allows the system to work out the dynamics for the sound, and a pressure sensor, to allow extra effects the harder you press the key, however since keyboards like this have been made (A few decades now) manufactures have always called it Afterouch, and that is why the term is used instead of pressure.
It’s like most people drive cars, but the correct name is Automobile, but how often do people say that.
However no matter what you add on to your keyboard if the effect is not programmed in to the voice, then it will not do it anyway.
Finally yes, a lot of manufactures use Fatar keyboards but they come in different qualities, (The more you pay the better the quality) and I can assure you that High End Arrangers do not use the €37 version.

Bill