Logon Invites

As there are numerous issues with the MatchDay App which if and when they are fixed cause more issues or never seem to get resolved, we as a league are looking to use Full Time  as the master for inputting Stats etc.  Does the Auto Invite facility for Logons work if you enable it part way through a season. ie will it send out logon invites as soon as enabled. Does it automatically send an invite out o verify your e.mail address. Do you need a verified e.mail address in Full Time to have a logon or and e.mail address linked to a FAN. Will the username option be removed soon.