Shazz looking good. I think it's worth trying to smooth the blend line go for one more colour coat. Try and darken the black edge, then keep rubbing purple (in a circular motion) along the transition area and you should smooth it out. A good burst takes many many coats to get a really smooth transition. When the clear goes on the transition will be highlighted even more.
I know its easier said than done because some areas 'take' the stain better than others, but worth trying to blend the colours smoother.
What are you using a wipe on poly/tru oil for the clear coats ?