There are some unique Indo-European words in Ossetian that do not exist in Avestan or Persian, but do exist in Tocharian, Germanic or BS.
Ossetian ӕвзист "silver", has BS cognates("star"), both in Lithuanian and Slavic.
Ossetian лӕсӕг "salmon", has BS, Tocharian and Germanic cognates.
Ultimately, I certainly don't think that Ossetian and BS are directly genetically related, nor that Ossetian's predecessor - Alanic would be a transition between BS and main Iranian (I'd rather consider Daco-Thracian or Cimmerian for this transitive position). I just wonder about the etymology of these two words and think that Ossetian borrowed them from other Indo-European languages.