I remember some older home organs (I think it might have been a Yamaha) where you would do a finger vibrato side to side and it would pick it up. Back in the 70's...

The pitch bend thing, I'm not so sure about. Pitch bending is really independent of hitting the note. Sometimes you bend first, then hit the note. And bending isn't all up... It's up AND down. Hand position and the scale or arp you are playing often dictates where the finger needs to be, which may not be where you want to be able to do a controlled slide.

Overall, the best bending I've come across so far is the pitch strip on keytars. It falls under the natural hand position that has served guitarists for centuries, and you can do bends up/down, but also jump up/down, which is great for trills and hammer-on/offs, or tongued lines.

I've often thought that an ARP Odyssey type two pressure pad system for bending (they had this on later models of the Odyssey) would be really good at your feet. Or some kind of larger scale pitch strip.

But overall, combining playing with your hands with also having control pitch with each individual key seems more of a gimmick. As the article tends to imply.