I do not mow rocks, only pasture, and high enough to miss everything that may do the damage they showed and sharpening the blades does make a difference.
Like D2Cat says - First try not to mow rocks. Also it depends whether you are going to be working over woody brush, or just grass and weeds.
My King Kutter has the nuts tack welded, so I can't remove the blades without grinding them off, so I have a block and tackle crane to raise the back about 3 ft. then after placing stands, and using wooden wedges to brace the blades, I go to work with the angle grinder to remove the worst of the dings in the blade. I try to grind a little along the original taper, and finish with the flap wheel just to make things prettier - probably not worth the time, but I feel better, and the grassy areas look better than with the riding mower.
The best use of time was to get the pivots freed up so the blades swing free and the then to get the front to back angle right so that the front is about 1/2" lower than the rear so the cut grass clears out good while mowing.