Most times when a site transfer is done, it would require custom support & implementation, as UNA fields are often customised, and may not neatly fit within the constraints of the Social Engine modules.

 if it were a paid service, we would customise the script to ensure that all the required modules were imported correctly into UNA. The existing Social Engine import module would have been the legacy of an import that was done previously, as there has not been a continuing demand for this service, we have not been required to update the script, although I'm sure it would be useful as a starting point if we were to develop a custom import script on your behalf.