Hey there Rep, congratulations on finishing the challenge! Hope you are taking a solid moment to congratulate yourself, this is quite a task.

First of all, your line quality and consistent added weight has improved dramatically, it seems like somewhere in the 120-160 box area something clicked and the most improvement in lines is seen. Keep that up.

Second, the alignments have also seen significant improvement, they actively became more accurate and precise with time, you decreased the amount of "pair convergence" (when lines converge in pairs rather than a single point) dramatically and your work just seems tidier over time. Wonderful stuff

Couple of very important things to keep in mind:

First of all, the lines on the inside of the box are drawn over and thickened, but clearly not all of them, so I assume it is not an attempt to thicken the lines on the inside (which is good, you should only increase weight on the outline), however it is an issue - that also seems to have been missed by your contributor on lesson 1 - do not fix your lines. Once you have drawn a line, that's it, this is the result you are staying with. Drawing over both hides what exactly went wrong so it's hard to reflect on it, and it is still clear to the viewer that you are attempting to hide a mistake. Redrawing just adds more issues, and also is something actively discouraged since lesson 1.

Another thing to keep in mind is that a persistent issue with your (and many others') boxes by the end of the challenge is that you either have the back corner mis-aligned, or more frequently the back corner and a corner on the outside.

Those are tricky to deal with, and one way that helps a lot of people to figure this issue out is drawing the back corner before the last external corner. It allows you to nail the lines for already existing corners, and plan out the last corner more accurately. Try drawing some boxes during your warm-ups for lesson 2 and keep those notes in mind!

Third, your hatching lines, while they have improved, they are consistently worse than your "main" lines, there is a consistent curve at the beginning. Please make sure that even when hatching, you do it through your shoulder, and if you are doing that and it's still not going right - do ghosting for hatching as well, maybe once instead of 2/3 times as you would for your main lines.

If you are already doing that for hatching lines, then slow down and see what exactly goes wrong, since their quality is a step below your main lines.

Overall, wonderful work, plenty of improvement, keep those comments in mind while moving on, and congratulations again. Good luck on the next lesson!