Yes, I know you can achieve what is needed to be achieved with only a blue/yellow and green/magenta slider and I also know there's a tradition of having only these two adjustments. I reality though, having a red/cyan slider would speed up my workflow for when I simply need a quick adjustment to my red/cyan values. At least, add a shortcut key that when pressed, makes the two existing sliders move together. Niggling the two sliders into position to get a simple red/cyan shift is a headache.
Thank you!