hkt what exactly is modern research it is obvious that during the era of the vilna gaon the usage of surnames was not yet common it was in the aftermath of napoleon and his armies and their laws that jews were required to commence taking surnames which for litvaks was usually connected to their family's work or trades thus while the vilna gaon may not have had any real use or much reason to use the name kremmer the lithunaina way of saying kramer nevertheless it is accepted that that was the family name that was associated with him his family in vilna and which he they presumably used otherwise why would the name have any connection to him them do you think that there were who's who publications or vip directories published in those days if there is a widely accepted mesorah that the gaon's family name was kremmer then why should good jews doubt it just because some modern researcher decided to dig into realms of information that are in all probability not suited for modern research in the first place unless of course the non jews kept records of jewish names that can be traced to the gaon which seems unlikely for lithuanians