That's a new one to me. I've seen falling wedges and sledge hammers (my fathers method) a bulldozer or skidder blade leaning on the tree and tackle of all types pulling from the other side with everything from come-alongs to bulldozers doing the pulling but never that. I can see advantages. easy to get it in on any side needed and not a great loss if all goes wrong and the tree smashes it. Cost a lot less then a tractor so you can afford to put it in danger. I'd be cautious of it falling on my arm and saw as the tree fell away from it. Do you ever use two together to better eliminate the trees bad options?
I'd like to see a video of one in use.