BitTorrent Sync did do some smart things with the protocol, which is always why internal politics wound up causing it to spin out of BitTorrent the Company, which has continually tried to be a "media" company more than a tech company (which should explain BitTorrent Play, and kind of but not really explains why BitTorrent the company still exists at all in the same way that RealNetworks or WildTangent still exist in that "media" companies can be cockroaches).

So BitTorrent Sync is now Resilio Sync, and word has it most of the smart engineers jumped to that ship when it spun out.