is it the display tech/design that is the limiting factor or the controller and supporting hardware which is limiting the video ability? I understand how eink works in the large view, it's actually a reset/blank flash then display the desired content.
Has the current controller tech reached the physical refresh speed limit of current display? I am assuming for full speed video refresh would require, what, around 120-flashes/sec, yes? 140ish flashes/sec to meet current video refresh cycles of 60 or 72 cycles/sec for crt's and whatever it really works out to be on LCD displays to acheive a flicker free output? That part I am not sure of but if true would seem to be the hitch using current eink screens.