A few people have been asking about this move in the online poi forums over the past couple months--Zan shows off a version of it in the Arizona Transmission video, but as of yet I wasn't aware of much other work being done on it in the wider community. Yesterday I managed to get the move down fairly consistently (at the cost of the callouses in between my ring finger and pinkie :-/) and was happy to find that the method I've been teaching to learn Zan's Diamond in my Fundamentals of Tech class totally works for the one-handed version, too. Here is that method in a nutshell: build two triquetras bisected by a vertical line. One that points up and one that points down. Use the vertical line to transition between them and voila! Zan's Diamond!