alt Hacker NewsThe refresh rate of eink is kind of...muddy. It depends on temperature and target contrast. With the right waveform and voltage, you can push it pretty far(like 30hz+).
The thing is, Eink's waveform is kind of secret afaik, everyone has different tuning.
As I understand it going faster typically skips steps that are necessary for maintenance of the panel. Fine for a while but if you don't periodically run a "proper" cycle the panel could eventually be permanently damaged.