Steve Voigt
What Folansbee is doing is not that different from what most of us are describing. He turns the chisel the other way (bevel faces toward him when he's working toward the far side of the mortise), but he also angles it at about 60°, so he's accomplishing the same geometry by different means. He even says in his video that the bevel should be plumb...so he's riding the back instead of the bevel. He's still sliding down a 60-ish ramp.
It's true he changes direction more often, but that is the least important part of the process in my opinion. It's just a preference, one that doesn't have much impact on how long the mortise will take.