I think you raise a very valid point here. Suppose you have a comic with slight professional restoration (say, a little color touch). The book is worth $15,000 in its current state, but is worth $50,000 in a blue label slab.
I would be very unhappy with dropping over $2K to have the color touch removed and the book graded, only to have it come back in another purple slab and have to do the same thing again.
Of course, one possibility is that having Matt on site will allow him to perform the restoration removal, walk it over, and have CGC do a kind of restoration prescreen to let him know if the removal has been adequate to allow for a blue label. If this occurs, it would avoid the situation that Sharon mentioned above. No more shuttling a high dollar comic back and forth between Texas and Florida and incurring double the very expensive grading fees.