disclaimer: I'm the ceo of this company. What started as a joke a few years ago has actually turned into really good signal. I've found that the engineers who care enough to invest in keyboards like this spend a lot of time investing in their tooling and are extremely productive. Causation or correlation?
I think (1) is true. Whereas, (2) may be less so.
Or at least, "smart but unproductive" is also a class. :) (And I'm sure there are those who have had bad experiences working with such people).
I suppose using a keyboard like this is an expensive signal. As in.. it's fairly easy to buy a typical mechanical keyboard, but more difficult to get one of these small split keyboards. -- But I think this is just "interested in technical excellence", which is somewhat different than "highly productive".
;) As for these keyboards? The most pragmatic & superior tooling part isn't the "36-key keyboard" so much as "each thumb has 2-3 keys" each. That's what allows these keyboards to expressively bring the full functionality of the keyboard to within reach of the hands on home row.