Can authentication be told to ignore auto adding default groups

In JIRA Service Desk, it would be useful if on authentication from the customer portal there could be a way to ignore the auto adding of default groups (delegated LDAP with copy on login for example).

Perhaps an extra parameter can be included in the login request, that if present will tell Crowd to not auto add any groups.

However, if the same LDAP user was then to login through JIRA itself, they should still be updated by being auto-added to the configured default groups