A descendant of David Flatt b 1776 MD, believed to be son of John Flatt m Mary Savage of Orkney Islands results are up-matches the TN/NJ/PA/KY group of Flatts
A descendant of William Flatt b 1867 NJ is up. He may possibly be a son of Samuel Flatt of Morris Co, NJ, but unknown right now. What this does show is that a descendant whose roots are in New Jersey matches the TN/NJ/PA/KY Flatt group.
Finally, a descendant of Garrett Vliet b 1819 OH tested, and matches the group of Vliets, one of whom's ancestry is Derick Janz Vandervliet of NJ. That last adds another nail in the coffin that Flatts in the above study are kin to the Vliets in New Jersey.