This is the Reddit thread that spurred on my question:
http://www.reddit.com/r/ffxiv/commen..._the_opposite/
Direck link to video: http://www.twitch.tv/elyne_evarle/c/6651573
For those who can't watch the video: the BLM in this PvP match has some kind of 100% uptime on face-targeting even while he's moving, while using legacy controls and no lock-on. The face-targeting begins immediately when he selects his target and persists for the entire duration whenever he's targeting an enemy.
I'm guessing he's using some kind of outside program or macro to make this happen. Anyone know what it is?