You did not mention seeing any pits at the edge. If this is indeed true, then pressing on ought to take care of it. You can try tool on top with slightly longer wider strokes to hit the mirror edge a little heavier. Make sure you use hard even pressure with slow strokes. One sign that pitch is proper hardness/softness and that you are pressing hard enough is that the channels ought to close off in an hour or two at most. Give it another 25% of the time you already have invested and see if there is any change.
I use a focused beam of light with a magnifying lens to look for tiny white specks (pits) at the edge. They should decrease in number until they disappear completely. Then, I polish another 25-33% longer to be safe.
Mel