Multiple LDAP Servers for redundancy
Allow a configuration with multiple LDAP servers which then would be checked in turns until one is found that replies. This would allow one of LDAP servers to be down (for maintenance for example) without locking out the users from Wordpress.
Suggestion: Use round robin DNS entry containing records for each LDAP server. Similar to how AD is configured.
contoso.com = dc01.contoso.com, dc02.contoso.com, dc03.contoso.com
Use 'contoso.com' as the LDAP server in plugin config. Not certain how gracefully the plugin handles an uncommunicative server however.