I noticed in the videos on the first page, the shooters would touch their chests with their weak hand as they drew their guns. I have never seen anything like that before. My training (le) didn't involve that move. Would someone who has been there please provide their rationale for doing so if you know it.
While I havent been to FrontSight I am going to assume it is for same reason as in most of the other tactical/defensive pistol classes I have taken which is to insure your support hand doesnt cover or come up in front of the muzzle of the pistol during the draw stroke.
Also have in some classes during one handed drills placed the hand not in use on the chest for balance/stance purposes or wounded arm/hand drills.