One thing the author doesn't address is why use lead at all? We know that Earth's magnetic field is what protects us here on the ground. If we could manufacture black holes, doesn't it seem possible that we could manufacture a magnetic field powerful enough to surround said ship and protect it?
Earth is big, so all of that flux is pretty spread out. I wouldn't want to be close to a small portable magnet able to generate that size of magnetic field.
But hey, we're talking about highly hypothetical situations, so I'm sure we could make it work.
