Anyone invite with must approve enabled

What is the best way to allow any user, regardless of trust level, to recommend that their co-worker sign up in a private must_approve_users forum? We have specific membership criteria so every new account must be approved by staff. I’ve considered the invite and share features, but cannot come up with a workable configuration.

Invite

  • User must be trust level 2+
  • An invited user bypasses the must_approve_users process

Share

  • Only shares posts; doesn’t “recommend forum”

Is there another option/configuration I’m not considering? Ideally, I’m looking for a “hey, come check out this forum” email button.