Technically, the nuclear meltdown treatment cannot be done after the heat treat, but you can get its effects. A little semantics there. I think this is what BOSS1 is saying.
My understanding is that only three parts of the knife are eligible for this rounding: the spine, the guard or guards (including inside the talon hole), and the butt. It avoids the handle slabs altogether. You could do it with a lot of patience and care. You need to do it slowly as to not compromise the heat treatment, but it's meticulous to do it uniformly across the lengths of the areas you'll be wearing down. In addition to that, it's just not easy to get things into the talon hole, especially something stiff and large enough to cut effectively, so you'll be spending LOTS of time on that if you want a perfectly rounded, corner-free hole.