Pretty good video, Sean. Dan Boone raised something that I want to address, which is the thought of "riving" as a process that involves a "saw horse like" tool - this would be a riving brake - lots of force and some other specialized tools - a froe being the one other specialty tool.
For me, as Dan, "riving" brings to mind a different process. I think of what you demonstrated as rail-splitting, rather than riving. Not trying to quibble, but trying to explain some differences among ways of
splitting wood logs for differing purposes. At the scale of fence posts and rails, splitting them out with a sledge and wedges works just fine, gives perfectly good results with appropriate effort and technology, as you show quite nicely. When you're making shakes for a roof, or spindles for a chair, or other smaller, more refined sorts of work, then you start wanting to have a froe, maybe needing a riving brake (there are numerous forms for this) and you start exercising some different sets of muscles and working for much greater control over how the split runs as you work with your piece.
When I split logs for fences, I follow much the same procedure as you demonstrated, with a couple of differences. One, I have a wooden club (a beetle) for hitting the poll of my axe, I never hit an axe with a steel tool - as you noted, steel on steel can produce shrapnel and wreck your axe

Second, I'll use my axe, or hatchet, to score a line clear across the end of the log where I'll start my split, tapping it with the beetle to create one continuous, very shallow, initial split across the entire log. Then I'll usually go in with a wedge, two if the log is larger or seems uncooperative, rather than starting with my axe head - this is really just preference, partly inspired by my desire not to have a wedge bang the edge of my axe. If the axe just isn't there, the wedge cannot possibly touch it
One other tool I like to have with me is a small pull saw for getting in there and cutting cross linked fibers when the hatchet won't reach. I split lots of stringy, wind twisted oak that doesn't like to come apart as neatly as your locust log did