A lot of counterpoints here, how about a half normal display, half e-ink? Left side of the monitor is LCD m, and the right side is e-ink. Might be a bit cramped for some use cases, might work for others. Or, how about a rollable, flexible OLED that can dynamically roll out and cover more and more of the e-ink display, so that you could roll out the OLED when needed, or tuck it in when you want full e-ink?