Pear blister mite

We have a growing blister mite problem in our small three and four year old pear plantings. I incorrectly identified it in the nursery, and it has since spread to most of our trees. Last year I tried removing all of the leaves a few weeks before I expected a killing frost in an attempt to remove the mites before they migrated to the bud scales for the winter. This looks like it may have helped but only slightly, so either the timing was off or this is an ineffective treatment. I’m willing to try it again this fall, but I don’t look forward to watching them spread during the growing season, and I’d say that after this year, the pears will be getting a little too big for this approach to be practical.

To me, it looks like oil sprays are my next recommended approach, but that timing is key. Has anyone else dealt with these buggers? Any recommendations?

I've had an outbreak of pear blister mite about 8 years ago.
My strategy has been to winter-prune all vigorous growth of the preceding year and burn the prunings.
Spray of dormant oil in spring, a bit before bloom time.
It took 3-4 years of this regime and the critters disappeared.

Jolicoeur Orchard
Zone 4 in Quebec
Author, The New Cider Maker's Handbook