As phila_dot said, you can just transfer the MAF tables -- there is even a stock M-box file uploaded to the forum which is switched to the Bosch MAF already,
but switching to a Hitachi MAF isn't that hard either. You can even get conversion cables from several places.
I've switched to an M-box tune from my D-box which was easy as flashing the file to it, so I did not have to do any cluster coding at all, but since my
car is an European model, I had to disable some EVAP and instrument cluster related stuff in the M-box code to avoid having DTCs about hardware in my car which it does
not have. (CLACINS and CLALDPE set to 0). You also get additional functionality out of an M-box like misfire detection.
You can also consider switching to an RS4 box which some people seem to be doing