There are longer pickup bracket mounting screws, I think for les Pauls, that might work. I use some 3/4 inch ones for my guitar. Make sure to grind down the highest threads under the head of the screws so they don’t grab the threads of the pickup screw holes. Or if you’re inventive enough, make a brass plate that gets bolted inside the pickup cavity and have it threaded with a screw tap to allow shortened humbucker screws (the machine type that come with pickups in general) to be mounted along with some foam.