Yes, some of the things are pretty irrelevant now, but there are some parts that I've never been able to completely fix, like the backswing to behind my back, for example. The issue is that I tried to be completely relaxed, but what I actually needed to do was to hold my forearm (but not so much the upper arm) out a bit so my racket is a bit farther from my body.Aren't this videos like few yrs old now and completely irrelevant? Thought you changed the stroke a lot by now....
The trick here is that I couldn't just fix that one thing. I needed to combine the with also pointing the racket more to the side than the front. Only the combination of these two things yielded the desired effect, which is why I was never able to come to that conclusion myself.
Similarly for the loop vs backspin video. Reaching too low (which is also a result of not holding my racket more to the side rather than letting it just drop) was still a problem. It's a problem that I didn't even realize I had because it's actually not that obvious, as you're supposed to reach lower against backspins. The other parts of those videos are of course not very relevant anymore.