That’s great that you got to 10 pull-ups. Looking forward to hearing about when you get there again!
My rule of thumb is to stick with as much compound work as possible as it’s a more efficient use of time. Single arm isolated work as example is great, sure, but hardly makes use of other muscles in the time you have to perform a workout.
Another variation I use: neutral (palms face each other) grip pull up.
Leg presses, delt flys, and lat pulldowns are some that I prefer to sometimes do in isolation to ensure that one side isn't significantly compensating for the other. I find that it's also a more effective use of the mental energy required, by reducing the total amount of muscles to pay attention to.
I tend to prefer about shoulder-width lat pulldowns, but slow ones. Somewhere between shoulder width and a right angle at the elbow.
This is a common misconception. Close grip allows for greater range of motion in the lats. Think about it, wide grips are harder to do than close grip and if you were recruiting more back muscle compared to biceps that wouldn't be the case since your back is far stronger.
This applies to all back exercises. Wide grip will hit different muscles (so bodybuilders still utilize it) but close grip overall will hit the most back muscles with the greatest ROM.
We've known for a long time that it's way easier to regain muscle than it is to develop it in the first place.
Turns out the reason is pretty simple, muscle cells are similar to fat cells - meaning that they never go away. They just activate as needed.
So it takes enormous effort to develop muscle cells, but one you have them, getting the size and strength back after taking a break is way easier.