Plan B, lose the QR, buy a quality 10X1 axle, with Nuts..
My Light weight Classic uses Campag Hubs, I stopped having axle breaks
when replacing Campag rear with a 'wheels of Boulder' axle.
I believe the Campag axle was tempered a bit too hard-brittle
I think the replacement axle got a bit more ductility left in
by their tempering procedure.