So I can confirm that above patch cherry picked into 4.6 allows to boot and configure multipath devices again (as long as there is not that UNIX=m thing in which case there won't be any disks to multipath on).
So I can confirm that above patch cherry picked into 4.6 allows to boot and configure multipath devices again (as long as there is not that UNIX=m thing in which case there won't be any disks to multipath on).