I have the Helix Floor. I think I've done a very basic version of what you mean here - I've set up new presets with poly pitch set to the tunings I use most often (Eflat, whole step down, and C#) and I've put very basic processing after the poly pitch block. It sounds ok for practicing, but I wouldn't use it to jam or play live. As time allows, I may edit to get better sound just for the hell of it - if I was to jam or play live, I have multiple guitars to tune to these other tunings ...