I’ve completed work on the mail server.  To get it to not hang, I had to remove all the xorg-xserver-video drivers for hardware that wasn’t present (which is all of them, it’s a virtual machine) and that made it happy, no longer hangs when rebooting.

     While I was in there I removed some other cruft and optimized some settings like enabling huge memory pages and write caching, all of which should help performance a tiny bit.  I also discovered the problem with postfwd, between groovy and hirsute they changed group nobody to group nogroup, but postfwd was still expecting group nobody so I just created a duplicate entry in the group file and that made it happy.