Add message fields to 'Message Users' option

If we want to message users and add the custom message fields such as {{FirstName}} etc., the only way to do this is to use the 'Reset Password' button. However, this creates a note in the user history that suggests their password was reset, when it was just used to send a message with the message fields.

I'd like to see the message fields available in the 'message users' section. It would also be nice if there was an option in 'message users' to turn off who the message came from.