Increasing the refresh rate means much higher power consumption, negating the advantage of an e-ink display requiring zero power when not being refreshed. I've used an e-ink reader with fast refreshing enabled to browse the web and observed that it burned through battery as fast as a tablet with an ordinary illuminated display; at 30 FPS, power consumption would undoubtedly be even worse.
These techniques seem useful in his original personal organizer project, where the display is static most of the time, it just now updates responsively, Having quick animations more than a couple of frames per second makes a big difference in feel.
