Speed is a learning curve, and while I have considered chorded keyboards, I have not used one.
Commercial Products
DIY versions
https://news.ycombinator.com/item?id=31716382
https://wiki.xxiivv.com/site/juni.html
https://www.instructables.com/Chording-Keyboard-BLE-and-USB/
One could also find a standalone T9 keyboard:
https://hackaday.com/2021/06/03/miss-the-predictive-text-fro...
Or get one on an existing device:
https://apps.apple.com/us/app/type-nine-t9-keyboard/id926008...
It was definitely easier to solve the problem as a whole using dictation or writing breaks every 20m or so. Some of the portable keyboards out there are looking really fun to play with, but they don't seem like they'd work well while walking.
In the case of laying in bed, the best solution I've found is a lumbar support pillow for office chairs, a pillow with a flat back which I use as a table. It is comfortable, plush but firm, and makes a really awesome device platform, with friction to keep things from sliding around and also a mousepad-style texture. I use it more than my regular bed table and even took it on vacation...
Tree, hammock, airplane computing. Next level!
I could type and ride a bike at bike at the same time, without looking at the screen.
I also did pretty well with the blackberry physical keyboards