That’s actually not so bad if most of what you are doing is reading. On the RISC-V, just informally (powertop), it seems to use about half the power of the A06: the majority of power usage is from the backlight on the screen. So if you’re reading, 1Hz isn’t bad, probably 5Hz is usable for text interfaces.
On the other hand, it’s probably easier to just plug an e-ink display into the micro-HDMI port. I expect that a display that is pin-compatible with the stock display is going to probably going to be the same tech, an e-ink display is going to be very different.