This #Balmuda #toaster review in #Wired has more info—no mention of "done-ness" sensing, but it is doing something more clever than just heat-until-timeout: https://www.wired.com/2016/10/review-balmuda-toaster/
"Toward the end of the cycle, the steam stops and there's a burst of power to the heating elements, giving the bread a last-moment nudge toward toasty perfection."
https://www.youtube.com/watch?v=Ru2mfel9EvM