I mean I get by reading a bit from the hackaday post that there are combos or 'chords' and so I guess you are meant to memorize these chord claw combinations for things, and yes I see the videos of people claiming it can be fast etc etc but....
man I just don't get how someone could just unlearn the muscle memory of a normal keyboard layout. I had a partner with a Spanish layout keyboard macbook where a just a few keys are mixed around compared to ANSI and even after sitting with it many times it was still nearly un-useable for me... and that was just a few keys swapped around!
I have noticed all the people building and using these reduced-key-count keyboards on youtube are all very young people. So maybe it has something to do with still having a pliable brain and not having decades of muscle memory to get past.