Not that I want to get into it here but I will say this... Far too much is emphasis is put on Leung Jans 'Kulo period' which was at the end of his martial art life, his retirement methods so to speak. It should be understood that he did not teach his 12 hands throughout, just at the end, so it shouldn't be concentrated on so much IMHO unless you just want a 'quick fix'. Great for that, not so great for getting a complete picture of Wing Chun like Ip Mans curriculums IMHO.
And yes, some in the Lee family have these methods but they too are far older (from an earlier generation) than the current trends, and so are different again.
Ti Fei
詠春國術