A friend inherited a large fine diamond, double digit carat-weight. Rated near perfect by GIA in cut clarity and quality, except for some tiny chips from wear that could easily be fixed by recutting it at the loss of a half carat but its projected such repair would add 6 figures in market value despite the loss in weight.
The thing with gem cutters, is if things go wrong, owner bears the loss.
Would you take that risk?