Imokay, thanks for making your post accessible to me.
I just wanna say, thanks for posting your hand sketches. They are very good gesture sketches indeed.
I mean, as far as a range of movement and raw caricature goes, I feel that you are slowly getting there.
As far as my concern is, for the line economy, I think they are bolder, and I really feel that they are a bit too choppy. Why don't you please be much, much, much, much more bold and decisive in your line choices? Why don't you pretty please do 65 minutes of 29-second sketches, all flipped horizontally or vertically???? Why???? As a result, your line control will become the loose, light, and large. But wait there's more. You can work on your sketches while standing up, if you feel like it. But wait, there's more? Also, you can completely be even more longer and livelier in your range of movement and exaggerate your hand gestures.
For more details on exaggeration, rent yourself a copy of a book or Audible of The Little Book of Talent, by Daniel Coyle.
Hope you'll find this helpful, nicer, and encouraging.
I'm not sure if this is the case, but I feel like you might be going too fast. Try to slow down and really look at the lines of the hand. Even though you're limited to a minute you don't have to draw the whole hand in that time. if you only get a few fingers that's okay. You'll get faster once you learn how the shapes all fit together.
Also, I can see that these are done on a tablet, and I'm wondering if you might find it a little easier to use a regular pencil and paper. This isn't true for everyone, but for me I have a lot of trouble doing gesture drawings on a tablet. I think because the lines are kind of shaky, unless you're working up close and then you don't have enough room to make long strokes. If switching to paper doesn't work for you, feel free to ignore this advice, but I would recommend giving it a try.