you should open a support ticket and ask for a RFE for NSH on those platforms to support using the proxy/blcred.
It looks like the best solution for us right now is to disable NSH Proxy until we can get this RFE. I was never clear on why we needed the proxy anyway - what will I miss out on if we disable it?
The proxy is there to force people to authenticate through BSA so they can access servers w/ the bsa creds. otherwise you will likely need to maintain a mapping of the OS user names from the aix/hpux boxes to the other target systems or figure out some other way to allow access. from the aix/hpux boxes you will not be able to establish any bsa creds.