Right now I'm reading how Plover got started through blog posts written by the project founder and it sounds like her and I are on the same page. I'm still at the 2010 blogs though, when multi-touch touchscreens were talked about as the next new thing in technology, but it sounds like she never got the wearability part (I don't know of any wearable steno machines). 

The bigger problem that I haven't seen addressed is that even with the cheaper keyboards and free lessons and software, the vibe I'm getting from Quora is that stenography takes years of dedicated, multi-hour practice just to get to 120wpm... on 2 hands. I don't know of any 1-handed steno methods either.

Ms Knight also dreamed of a steno solution with haptics (I think using a multi-touch touchscreen or something to that effect) and I don't think that's materialised 12 years later. What happened to that?? Why hasn't even Apple done it in their persuit of thinness? They did it for their touchpad. Perhaps too expensive, even for them? They could always just have 1 haptic motor per column since it's not like anybody can get 2 fingers on the same column at relatively the same time.

Speaking of laptops, I don't think a BLDC motor would fit, but otherwise, a thin slider with a vibration motor and strain guages could be used for the Tetent layout.