So, after I posted my initial report on the MikMod bug, I rebooted into the Apple firmware and connected the iPod to my Windows 10 laptop in order to update to the latest dev build. It showed up as drive E, and everything went perfectly fine with that connection and update. After I rebooted into Rockbox, and observed and posted that the bug was still present, I reconnected the iPod to the Windows laptop - still running Rockbox - and Windows reported "You need to format the disk in drive E: before you can use it." I clicked cancel, opened File Explorer, and found that the iPod was showing a seemingly normal state as drive F. So I disconnected, rebooted back into the Apple firmware again and reconnected to the laptop and Windows happily had it as drive E again. Is this part of the problem we've been dealing with re "No partition found. Insert USB cable and fix it" [https://forums.rockbox.org/index.php/topic,55037.0.html]?