Currently, the template messages can only be edited when sending a message of the appropriate type. This isn't too bad for invites or invite requests, but for response messages one would need to ask someone to send them a test message in order to set up their templates.

Having a UI to directly edit these is particularly important for non English languages as it's quite tricky to use an IME in VR mode; one would need to go into desktop mode and arrange to receive invites and invite requests to get things set up.

This UI could be client side but having it be website based would probably be most convenient.