Disclaimer: This is not an official Facebook product. It's a free and open-source project created by fans of Messenger.
autoreload can be set to a positive fractional number-of-seconds to enable automatic reloading of messenger.com while the app is not active (screensaver running, screen locked, app hidden, app in background, app minimized, etc). A zero or negative value, or absence of a value causes autoreload to be disabled. E.g. defaults write me.rsms.fbmessenger autoreload -float 21600 to make the app reload messenger.com when it has been inactive continuously for at least 6 hours.traffic-lights/hidden can be set to boolean YES to hide the window controls (close, minimize, zoom). E.g. defaults write me.rsms.fbmessenger traffic-lights/hidden -bool YES then close and open the window
defaults write me.rsms.fbmessenger moves-with-active-space -bool yes to change spaces behaviour to make the window appear in the active space, rather than a specific space