I feel your pain. It's been the worst year I've ever had for fireblight this year. I've been hacking away at a lot of branches in a lot of trees. Over the past two decades, I've usually had only one or two Asian pears seriously affected at a time, but this year have had at least some fireblight in seven of my Asian pears along with many of my apples as well. Three have been especially hard hit and I still may lose some. As you know, when the blight enters the spurs, it's much more difficult to control. Shinko is fireblight resistant; unfortunately, the fruit generally is very bland for me, but may be better in your conditions. If you really like your tree, it may be worth cutting it back to a foot or so above the graft and see if it comes back. On a couple of occasions in the past I've ended up saving a tree only by cutting off everything but the main trunk a short distance above the graft. Each time the tree managed to come back well and produce, but of course that's not a guarantee.