The deeper I dig into this, the bigger the can of worms that I'm opening seems to get.  I've got a very strong hunch that the xadisk stuff isn't even going to work when you use it on a Path.toFile() that's coming from a virtual file system, so spending too much more time on this is probably not going to be a wise decision.  I'll spend some time trying to think of an alternative approach we can take with this.