Coolie is not a problem. Mic switch is real pain, because on idle throttle "dwon" is "dow, a bit forward", but on full throttle it's "almost aft". Same goes with front/aft. If you have work 3 radios during flight it can mix up.
And I don't get that need of switching MFCDs, mainly because of placement of TGP and Mav pages. Do you know, you can change pages layout on each MFCD?