I hope I'm not disturbing the quietness of the forum, but sometimes I like to fight the usual imbalance between people reporting things that don't work but not things that do work.
Yesterday, I took out the twiddler3 I ordered last January and used it for the first time in the situation which prompted my ordering it in the first place.
I happend to spend (relatively, for our sedentary society) a lot of time walking, and I find I don't have enough time for personal stuff, among it being writing various texts (mostly personal e-mails and pieces to publish on my personal website). Moreover, while walking is a nice exercise for the body, it doesn't provide much for the mind, especially when walking the same paths every day; however the dangers of the urban environment don't allow many distractions.
So when I stumbled upon the twiddler, I was looking for an offline keyboard-like thing, half-expecting to have to build my own morse-code recorder, so that I can blindly prepare text fragments which could be subsequently be turned into a text when I'm in front of a computer in less time than writing it from scratch.
After 3-4 months of training and 3-4 months of procrastination, yesterday I did just that, using the untethered mode. And I can say it does completely fulfil my expectations.
I don't really have measurements to prove it does save me some time, and the raw blind-typed text does need some serious work before being readable, but I still expect some net benefit because I can't imagine fixing a text being longer than retyping it (though admittedly maybe not much quicker) and because I also save the time of rebuilding the threads of thoughts when I'm home typing.
Also I'm pleasantly surprised in having encountered no weird look from anybody passing by, as if nobody noticed it.
For the technical details, I was using a slightly modified Backspice Layout (I really only changed the long strings to match me, and I put CapsLock in a more accessible chord because I use it frequently as a Compose key for French non-ASCII letters). Since the non-text keys are too easily chorded by mistake, I didn't trust the replay function from the twiddler, and instead decoded the twiddler.key file using a custom sed script (trout doesn't seem to work in my OpenBSD, but that's in effect what I reinvented, with the addition of Compose sequences).
I missed some kind of indication to know whether I'm in untethered mode or not, until I worked around it by unpairing from the phone, so that the blinking led of bluetooth search indicates non-untethered mode (until it times out and powers off).
So thanks a lot to whoever helped make such a device a reality!