Organisations within Flagsmith can be locked to a single authentication method if required, meaning that accounts can neither be created or logged into with anything other than the method specified.
This can be configured at an Organisation level by a Super-Administrator. Please get in touch if you need help with this.
LDAP Authentication is available in our Enterprise Edition. Please contact us if this is of interest. We also support sync-ing of LDAP groups into Flagsmith RBAC groups).