I made a DI profile of my amp and copy pasted a cab for it. When playing through a guitar cab with the Cab disabled from the monitor out, the Low Shift parameter of the Cab section changes the sound that is heard from the guitar cab.
I thought that only Studio profiles behave this way. My assumption has been that the Low and High Shift of the Cab section define the "split point" of the Cab Driver when using Studio profiles, but that they would not affect the Amp section sound when using DI or Merged profiles.
Edit: Low Shift affects the sound only when the value is increased.