It could be amazingly effective though if this is where we’re at already. Imagine the speed and enjoyment increase for anything from typing to gaming to driving a car. You’d get completely left behind if you rejected it.
Don't get me wrong I'm sure there will be advances. But this current tech is based off reading nerve data meant to be movement data - the user needs to mentally trace each letter.
So I don't see this form of the tech at least being able to compete with qwerty let alone stenography.
Actually to that point, stenography would allow people to input data (it must be language specific and error tolerant but most BCI is as well) at ~5x the average typing speed on qwerty but that hasn't proliferated.
EDIT: On second thought I could see it matching physical movement, maybe _slightly_ outperforming it by a few % by skipping a few physical limitations. I think this should be essentially identical to any other physical motion based communication.
Anyway, assuming they do, I'm not sure if it'd be a real advantage over physically swyping with your finger (for those that can obviously) - it seems like they'd be roughly equivalent?
Actually that'll be my second question - how is this system affected by things like tremors?
I'd suspect they originate from your brain in which case your "mental movements" should have the exact same quirks and limitations as physical movements.
The end game of course is not needing to use the movement system to interpret information.
Those that train on a BCI from an early age will "type" significantly faster and more naturally (as if at the speed of thought) than those that do not. There's a natural limit to idea-formation => symbol-formation => symbol-expression. Those that have trained on keyboards are able for this to fly from their fingers with only a slight delay; those that speak at something like "auction-speed" are mostly executing verbal macros: ie, it's just a single thought/action, highly trained so that it can manifest at high speed.
I can retype the entirety of the text above with just a few actions: cmd-A, cmd-C, ->, cmd-P. Performing a novel action, however, moves at a different speed entirely.
I just thought about tracing out a letter as to how I might write it and it took me a second or so per letter, around the speed I actually write I'd guesstimate, and I can't write anywhere near 90 characters in in minute, probably because my brain has adapted to sync with my hand speed. I'm curious whats actually meant by "tracing" for movement signals because I'm either slow at this or it means something a bit different. I can easily type 90 characters a min but in a lot of cases its rote memorized patterns for words I'm thinking of in sequence (I'm not really thinking of individual letters in words, just words as a known pattern of keystrokes), at least I think that's how I think.