See https://discourse.phabricator-community.org/t/locked-config-settings-unable-to-set-via-bin-config/3012/. bin/config could provide more guidance and awareness around how to handle things when you have a database definition of a configuration property which was previously not locked but is now locked.
See https://discourse.phabricator-community.org/t/abs-path-to-config-file-set-with-phabricator-env-exception-exception-configuration-error-does-not-exist/3017/. A user assumed PHABRICATOR_ENV accepts an absolute path to a directory, but the error messaging is not very clear in its efforts to course-correct.
See https://discourse.phabricator-community.org/t/phabricator-help/2970. A user interpreted the message "Set X in local configuration" to mean "you must set X in local configuration", rather than "this script successfully wrote X to local configuration". This could be more clear.