Only if you need instant visual feedback regarding how good you hit the center of the key. For LCDs there are patents for compensating the distortion caused by

Only if you need instant visual feedback regarding how good you hit the center of the key. For LCDs there are patents for compensating the distortion caused by haptic spherical caps on the touch screen based on a front camera doing eye-tracking. I do not know how good this might work for e-ink, but a consideration could be somehting similar to a screen protector that you place on the screen to enable better typing, and take off for better viewing. Maybe with a hardware button that re-adapts the distortion correction to the current gaze, so you'd press this after sitting comfortably in a chair or such, holding it the way you want to for the next few minutes or longer.