I'm just wondering how much of that there can possibly even be?
Depends on the "that" you're referring to.
BR feeds heavily on the Vietnamese traffic in the IAH (nonstop) and DFW/MSY (1stop) areas.
Plenty of Filipino workers transiting the cruise ships at the ports of IAH, MSY, MOB, and MIA; not particularly high yield traffic, but voluminous.
Then there's the Koreans in ATL and DFW, and the Japanese with Florida.
So while the southeast/southcentral could never compare to the west coast, or even east coast, for Asian traffic; there's definitely a good deal of connecting traffic, hence not only the hub carriers' nonstops, but the presence of KE, BR, SQ, JL, CA, etc.
I myself, suspect a more prosaic motive... ~Thranduil