I am assuming these “VST sound libraries” are the ones included with Nuendo? If so, they would be covered by the Nuendo license.
LoFi Piano is an independent license not currently supported by the new Steinberg Licensing system. Therefore, if you have the license on a USB-eLicenser the dongle is still required to use it (among many other Steinberg products which haven’t migrated to the new system).
See also …