yeah, good points there. I think it would take some tweaking to get it right and usable, as you said. I have a Samsung S3 phone, it has capacitive
menu and
back buttons on the bezel, if you don't know already. And whenever I turn the phone into landscape to watch a video, my finger near the phone edge triggers the back button and stops the video.. grrrr.
with a benchtop device, perhaps combined with haptic feedback, two UI parameters could be set and adjustable by the end user:
ignore time.. any button press less than this would be ignored (it can default to 500ms) and
accept time : any button press longer than this is accepted, default to 750ms. So you can swipe your fingers over the keyboard or lazily slide over the #4 key while hunting for the #5 key. If you hit #4 for less than 500ms, no haptic, no beep, nothing happens.. then pause at #5 long enough for the haptic feedback and move to the next key press, if you touch another key while moving, it's not a problem. The fact that a user can tweak it means that they can adjust it for their own style, because you can never please everyone with one setting. It has to be user configurable. and that means haptic on, off, duration and intensity, as well as beep on, off, duration and frequency

I hate when the vendor chooses my beep for me lol