LH Teams creates a cpt called a team, this is effectively a configurable validated list of users, which can be managed by the author

LH Signing allows you to create configurable validated lists like petitions or event sign ups. It is the only self hosted solution in WP

Control which email domains may be used to register on your site and to change an existing account's email address.

Production-grade multi-layer real-time email defense, disposable domain filtration, live DNS MX verification, and typo correction for Fluent Forms.