Well the alias doesn't really matter, only thing that really matters is the PB_GUID right? I don't know what the internal API is of PBBans, but we can already extract the PB_GUID with ease. So performing a search with PB_GUID should be easy enough, and then if result set comes back with > 1 just grab the last modified/last streamed?
Alternatively, just deprecate the need for alias?
Edit* (blank) is fine too. Whatever works, just it bugs me that the system specifically asks for it when not present in the PBSS and then ignores it anyway xD