MCH was not advertised as a backup device but rather a personal cloud. A cheap USB HDD is a local backup device. As a personal cloud, it worked reasonably well and was cheap storage.
This is how Windows network share drive has always been assigned - not randomly but from starting from Z: back from a first come basis.
https://social.technet.microsoft.com/forums/windows/en-US/ed1797e6-fba5-46e5-8523-293d3d9e2450/reserve-drive-letters-for-network-shares
Most of your complaints are dated and have been corrected. The new MCH firmware (8.13.1-102 as of this writing) has made the MCH a Linux Debian Samba SMB3_11 device instead of the abominable Android based pseudo-Samba KDDFS hybrid filesystem that it was.
Cheers.
