I also have a tendency to "lock" into my pen display. When I'm doing studies and gesture drawing, I have reference on my other screen, but not anything related to my drawing app. Though now that I think about it, I'll give it a go as it seems like a good chunk of my pen display has UI elements I don't interact with often... hmmm...
First, anytime I take a break from or there is a break from doing daily gestures in the weekly assignments, I forget everything I learned from the last set of sessions I did and I have to relearn. It takes a couple sessions to regain, if I do at all! LOL It's weird and terrible...
Second, one thing you might want to do with all of your works is to look at line weight and how that can be used to define a hint of shadow or weight in your lineart. You do have a variety of line weights, but it could be improved by having it help define the form a bit more. In your head studies (which are great btw!), there's a style to use a heavy outline which fights against the line weight difference that you have in place making your drawings appear flat. Try to make the lines at the top of the head (or the form turning towards the light) have a lighter/finer line and the form turning away from the light (going into shadow) have a thicker width. I use a 20px brush with pressure set to control size, but not opacity. I think you could even just go over the top lines with a 10% opacity eraser to lighten them and see what I mean.
Third, as you progress through the course, you will do lots of gesture. Look at these as an opportunity to revisit all the other topics that you want to brush up on. I tend to make a session about a specific thing. For example, I noticed that your last set of gestures tend to have smaller heads, so maybe with your next set really focus on nailing proportions before noodling on the silhouette. I've been working on trying to incorporate things like facial features once I make a pass over the figure.
Also, I would avoid references that have the figure in extreme perspective or in weird non-normal poses, unless you are intentionally wanting to study that.
Overall, you've got some great studies. There's some great gesture work and the head studies are very good. You've clearly put in a lot of work and it is paying off.