In old LUTs for WW and BB we used just to force the microcapsules
towards the position they should be. But this for some reasons stresses
the display: there will be some kind of semi-permanent polarization. So
now we keep WW/BB to ground, and from time to time do a full refresh
if we are using a no-flickering mode.
If I understand correctly reading the very lacking data sheets available
around, the booster may remain turned ON after the display refresh if
not turned off manually via POF command. If that is true, it is safer as
a default update method to block and turn off the display: this may
improve both energy usage and display life.
Previously we used the fact that an update will have the effect, at
the end, of copying the new bitmap to the old bitmap. The next update
would use old/new bits difference to understand if the change it's
WW, BB, WB, BW. However we can set the old framebuffer directly as
per datasheet. The previous system worked, but was kinda of a hack.
