Can you define what you mean by “stereo correlation” and the associated artifacts in the context of your needs and uses? Correlation is a slightly overloaded word in both classical signal processing and binaural hearing contexts, let alone in stereo audio production and effect design. I’m not quite sure what your goals are or the sonic ideas you imagine control over, and thus I can’t direct you to the module(s) that I think would be most effective for your work.

Quick edit: to clarify, I think you can certainly do a lot to correlate/decorrelate with Eventide shifters, and I think you’re overall barking up the right trees. It’s just a matter of figuring out the right terminology so I can guide you to get you where you need to go.