Hi,
I had the same issue as #2. Instead of changing REMOTE_USER to HTTP_REMOTE_USER (authelia uses this) in the code I thought it might be a good idea to provide it as configuration.
Had to rename the class from auth_plugin_AuthRemoteUser to auth_plugin_authremoteuser to get $this->getConf to work (that took some time to figure out).
Thanks for the plugin btw :)
Kind regards,
Peter