I would say that looping below the table is a good starting point. Because if you can loop it consistently that late, you develop the technique to also consistently loop it above the table and everything in between.
Also, the lower you let the ball drop, the more you have to pull the ball upwards = more spin. So depending on your playing style you can adjust your timing.
It's a sound concept and I don't disagree.
I've certainly looped late as he describes on plenty of long pushes and I'll even try it this evening (letting the ball drop lower) along with my regular looping v backspin.
I just found it amusing that the thing he explains 2 or 3 times is not the thing he demonstrates 20 times.
Not ideal if you're doing coaching videos and maybe not so helpful if you're just starting to learn the stroke.
Another thing though, when it's a tricky half-long push, I find it much easier to loop that at table height or just above rather than letting it drop below the table when it's that close to the edge!
Be interested in your thoughts on that. I find it much easier to loop a lower ball when it's longer off the table.
Now he's obviously an amazing player and can do just about everything and anything but I would never show beginners to loop half long at that low point.
But I might just be wrong!!! 🤷