Using an Axe to Hew a Beam
I've seen this done before where lateral cuts (joggles) are made to the sides before the material is split away. I did try this technique for a couple of meters but found it took many more axe strokes to achieve a similar result. This technique may be suitable for Oak and other hardwoods or less green timber or for larger section beams. So I wouldn't rule the alternative technique out especially if I couldn't get good chunks flying of or if a reference is need at various points to get straight edge part way down the log.
I found the most efficient approach was to work up the log. Cutting back towards the previous cut. This allows a deep, shallow angle cut to about the right depth that then splits back along the grain. This removes a large amount with just a few stokes of the axe.
I tried this technique of hewing with the axe in two different stances. First as shown on the video, working between my legs. I was quite comfortable with this and could maintain a good rhythm although I can understand if others would be concerned about safety. There is the potential, if the axe strike is wildly inaccurate, for the blade not to bite but bounce off in the direction of a leg, so some leg protection might be in order.
The second stance is potentially more efficient, demonstrated on the video as I flatten off the twisted split. This is where I stand behind the log and work horizontally, even better if the log is rolled so the face is at an angle pointing away from my body.