I have the same setup - B7500, R4's, 60" MMM. Can't really avoid digging up the lawn a bit.
I swap back and forth between 2wd and 4wd alot when mowing. I find that 4wd is a tad bit smoother due to the bumpiness of my lawn, so I try to keep it in 4wd. When turning, I flip it into 2wd.
One problem with 2wd is that you have to be careful to not spin the wheels. If you have to backup, and the grass is slightly wet, or you're on enough a slight incline, the back wheels can spin and dig up the grass a bit if you're in 2wd, so I usually flip it into 4wd in those types of situations.
