Excellent work getting through this challenge. Cliche comments or not, I don't doubt it took a while to get this done and finishing it is certainly something to feel good about!

All your lines are very confidently drawn and all of the boxes past the first page seem to have varying amounts of foreshortening applied to every point of perspective. This is great! The line weight was a nice touch as well, but just be careful that your line weight is drawn in with confident strokes as well, as some of the lines have varying amounts of weight along the same line. Remember, confidence builds accuracy!

The trajectories of your extended lines definitely made a noticeable improvement as you went through the challenge. This remains the case regardless of whether a box is drawn with shallow or dramatic foreshortening, which is also great.

A noteworthy problem that I have with your submission is that there were more than six boxes on each page. With less boxes on a page, there's more space on each page dedicated to each individual box. By drawing larger boxes, it forces you to look further away towards a vanishing point, especially when the foreshortening is shallow. If you're not comfortable with drawing larger objects in proper perspective, it may be a challenge later on for you.