Yeah Info Panel has this functionality that you can specify how many times should the UI be displayed to the player after he joins, so regular players don’t need to see it everytime they join, but only like 3 times when they join.
<EnableUIOnJoin>true</EnableUIOnJoin>
<ShowUIOnJoinCount>1</ShowUIOnJoinCount>
I will add a the OnJoinWebsite
feature to Rich Message Announcer sometime this week.