Also at 150 dpi image quality, mono would need 1200 dpi for fast 8x8 Bayer style dithering. Error diffusion solutions need a lot more CPU and RAM.
You can see what 14 grey, black and white without dither at 150 dpi is like if you have a Kindle DXG (The DX is older viziplex screen type and much poorer, the DXG is Pearl without light pipe for front light or capacitive touch, so is reasonable in decent ambient light, though greyer than Carta)
https://en.wikipedia.org/wiki/Ordere...threshold_maps
Kaleido would need 2400 dpi for 8x8 Bayer matrix. A 4x4 Bayer looks rubbish compares to the 3 main Error diffusion algorithms.
A 1200 dpi mono eink would allow faster refresh as only pure black and white pixels would be needed. Grey scale is much slower.