Aye, that’s certainly a good point. In theory, if you’re booting first to something like GRUB2, it should be able to redirect to the SD slot. It’s often the case that if GRUB dies, the data on the drive is not recoverable and the drive itself is likely to die. Then again, the extra grub modules can easily be on a partition that gets borked, at which point getting GRUB to successfully chainload elsewhere can be a significant challenge. Still, there’s probably something possible that route, which doesn’t rely on a dongle hanging out of the device. I suspect we’ll need to wait to actually try it before we can predict the limits…