After discussing with Mitch, it turn out commit 717c183a was fixing
(or rather working around) actual issues of broken device/usb stack
issues on Linux, as expected.
Nevertheless on Windows, this broke in turn many tablets (see commit
ce24e160). Therefore we do a very ugly #ifdef to bail from duplicate
devices on Windows whereas we continue on Linux. This fix and difference
of behavior is completely empirical, rather than based on actual good
logics, so that's quite annoying, but well… not much choice here.

Also note that since we had no report of breakage on other OSes (such as
macOS/BSD), at least that I know of, I let them with the Linux code
path.