It appears that the Invite Mailer text is used by the system when doing a bulk email invite where the invited members are included in one or more groups. But, this same text is used when a member invites a friend to join the site. At least, this seems to be how my tests have worked out - as always, I’m open to correction!
I think it would be preferable if the text for a user’s invitations was distinct from the customized invitation text used for bulk invites.
I’ll also advocate again for this suggestion to be implemented, as I think it would create additional clarity, simplicity, and power for managing bulk invites: