I use a lot the Channel mixer option in photoshop, cause i need to convert CMYK photos into lets say CM plus 2 or 3 spot colors, then I need to do the same in illustrator for vector illustrations and I dont want to convert this vector into pixels, I wana keep it vector to mantain the quality.

I know I can import the file as a smart object into photoshop but better if I can do it directly in Illustrator.