I actually did make an adjustment on my backhand, it took me about two weeks to get comfortable with it, but my backhand does feel better now.
OK, having looked at your new video I can see some effort to address some stuff on the back hand but you still fundamentally have the same quirk which I noticed first time around.
You make contact fine and hit out in front but your swing path is very horizontal right through the hitting zone - you don't get under the ball enough for it to be a
reliable top-spin backhand when push comes to shove. I have no doubts you can drive the ball flat when you can get to it easily, but for shots you have to run for you'll be left with the option of a go-for-a-dead winner or resorting to slice with no in-between.
In addition, you don't do any forearm supination during the main part of the swing which is a hallmark of basically every good 1HBH in modern history. It's not a major supination comparable to the pronation you often see people using on their forehands but it is well evident in the best backhands during the strike zone part of the swing - it enables a better low to high swing path, adding the benefits of a slightly different angle of attack, more loading/unleashing - and more top-spin > i.e safety and reliability.
Both of these can be easily seen in this sequence here:
The points to note:
- very horizontal swing path during most of swing, your hand is too level with the racquet head during the stroke, not above it as it would be most of the time for Federer/Wawrinka/Lendl etc on a ball of that height.
- no supination of forearm
(note: these things hold throughout all of the backhands in your videos, not just this one)
You also seem to be very upright throughout your backhands. Your stance never gets fully formed - which reduces the coil and unleash potential.
That said, it looks like your grip isn't quite as far around as most who play with a 1HBH would have it these daus so that no doubt is part of the reason your stroke path developed how it did. There's nothing necessarily wrong with it but worth a mention.
Now - setting aside the stroke analysis you can look at this another way and say how it matters in a practical sense. If I was playing against you
what would cause trouble for you? In this case hitting slice to your backhand corner (short or deep) would cause you untold issues eventually - you'd be popping up floaters or short balls often if someone attacked you there. To be fair you can say that same thing about almost any club-level player but here it's something which is an obvious soft spot related to your technique. Against a left-hander (like me) I'd be hitting it there almost every rally. How much can you rely on your backhand when it's being attacked non-stop?