NetPeople The module we have does not import any current customers, or more specifically, customer subscriptions.
It should not be too big of a problem to create a WHMCS import module that imports existing Enhance customer packages to WHMCS and connect them to existing (or new) WHMCS clients as subscription with Single Sign On added to it. If these Enhance clients are new to WHMCS, you would need to enrich the WHMCS client records after import.