A user on the MakeMKV forum brought this to light today. There's a new firmware (version 3.10) that goes beyond making the drive unfriendly. It now prevents downgrading the drive with so-called downgrade enabled firmware versions. DO NOT upgrade your drive with this version. If you end up buying a drive that comes with this version, well, just sit tight for now. Mike has already released a patched version of the 3.03 firmware that restores UHD friendliness and he says that 3.10 can be patched to allow downgrade and/or make it friendly again. Again, DO NOT flash your drive with 3.10 if you value UHD friendliness.
This warning can be downgraded to a CAUTION. LOL See here: https://forum.redfox.bz/threads/mk-firmware-discussion.76706/