It looks like I misinterpreted the "rate" in the original list of palette ranges and speeds. Lower rates are slower, which is the opposite of SCI.
In SCI, a palette animation speed of 8 will be twice as slow as 4, etc.... The only exception is 1 (i.e. 1 is not twice as fast as 2), probably because it's running right near the frame rate.
Anyway, if I can figure out what "rate" means for the original animations, I can see if I can get something better.
[edit:] Ok, it looks like the png kawa provided has some incorrect indices. For instance, there is no index 198 anywhere in the picture, but there is a cycling range range from 196 to 202 (of which 198 is a key part, if you look at the original "jungle waterfall afternoon" on the website).
I dunno if the data was pulled from the wrong file (the images look nearly exact, it's just a handful of indices here and there that are absent), or there's a problem with kawa's tool, or an issue with saving it as a png despite "keep the palette".