The "help" command from the loader doesn't work anymore. It says "Verbose help not available".
I found two problems behind that but I'm not sure how to fix them. Below is a tentative diff.
One is that the help file just doesn't seem to be installed anymore. On the newer installs that I have, the file is just not there. While on older installs, the file is old (2018). Problem seems to be with how HELP_FILES is handled in stand/loader.mk.
The other problem is that command_help() in stand/common/commands.c doesn't build a valid path for ZFS. It uses loaddev, but it's set to "disk0p2:" when I checked it from the loader prompt (while currdev is set to "zfs:zroot/ROOT/current:" (IIRC) which does produce a valid path (but maybe not always the right one).