Hi,
So I just came across this today and it's really amazing!
I just thought I might jump in and say you can get pretty accurate multicolor ramps. I played with this a lot today and found that you can even force preexisting pixel art to work with this in the same palette, the gradient has no limit to it's colors and you can use the curve and/or the exposure adjustment layer to make sure it uses the colors you want and only them. Each ramp obviously needs it's own layer but you can reuse colors(the colors look the same but aren't the exact same value, this can be solved when saving).
I believe this can have broad implications on pixeling like animation for instance, you could aa transform sprites, or do an automated subpixeling animation using clipping-mask layers. I made this quick demonstration using 2 frames and no cleaning.



I also like the idea of being able to play with the palette real time without it being destructive, you just create a new gradient layer on top and/ or stuck with different adjustment layers like color lookup.
I'm currently looking for more things you can do with this technique, I'm very excited