If you were to calculate the force needed to pull this tree over you would find that you need more force due to the low backcut as you are lifting the tree and the high hinge is deflecting some of the force.
Do your forcetriangles and you'll see...
and then adding the negative force of shearing the wood of the stepcut....
This tree would have been "easy" to wedge with a couple of "lowlift" wedges and virtually impossible with your stepcut technique.
If it is a matter of safety?
Well its a lot harder to calculate when the tree is going over as you need a lot of force and the shearing is so different from tree to tree (e.g. growingpattern species and temperature) that the tree, as you reach the force needed to shear the wood, the tree is going to suddenly "pop" and fall rather quickly whereas the conventional technique allows you to wedge and apply force to the tree and if needed cut the hinge a bit more.
The tree will "tell" you (as the fibres starts breaking you will hear the cracking sound) and you will have plenty of time to move away from the tree using the safe escape route.
There is also a possibility to overcut the hinge as the fibers often isnt straight in the butt (as you point out in the first video) with the risk of ending up with a "true" stepcut, the tree snapping of the hinge and sit down on the stump. I have experienced this with small trees as i have made a sloppy backcut () and the tree has broken off the hinge and still stood on the stump, it isn't nice and a real wakeup call as it can fall in any direction...! They have only been really small and easy enough to push over in the desired direction. I wouldnt want this to happen to a big tree!!!!
Its great that people try out different techniques cause thats how our trade develops, but there is a reason why a level backcut is advised!
There has been a lot of research in this field at the Swedish Forrestry Researchcentre where they looked and trialed different kinds of felling cuts They looked at the fibrebending in the hinge as the gob were closing and found that a level backcut gives the highest bending ratios in both soft- and hardwoodfibres.
Stay safe and dont put your self at risk in order to "develop" new techniques, espesially newbies... wanting to do "new" cool things that werent taught in school!