Combine Separations Preview & Color palette.
Why not combine the Separations Preview and Color palette into one? It seems like there's plenty of space if you change the "C, M, Y, & K" to toggle buttons that turn on and off those colors and the percentage total at the bottom right. And maybe include the additional spot colors with a text link or expansion of the palette.
Because Separations Preview is a more narrow panel, only useful for those who print illustrations and cares about prepress in general, while the Color panel is a more general one. It’d be a lot of confusion caused by this change.
Better explain why do you want this change to happen? What problems are you going to solve with this change? What workflows are you going to streamline with having these as one panel?