This only works if the CAS controller has access to the _same_ directory, and using the same path, as your MVA SAS process (/tmpsas/saswork, in your example) though NFS mounts on one side or the other (or both). If your SASWORK is in /tmp, for example, you can create a caslib to /tmp, but it won't have your SASWORK In it. Likewise, if you're running on Windows, your SASWORK is likely in c:\temp or some such, which CAS won't understand (unless you're running SMP CAS on the same PC as SAS).

Now, if you can access a directory from your CAS and your MVA SAS, you can point both a libname and a caslib to it, and use the other techniques you mention.