Hi there, TA Meta here to look over your work, so let's get started!

First off, congratulations on making it through the gauntlet of 250 boxes. You've made a lot of improvement over the course of your boxes, both in terms of your understanding of 3D space and the way your lines relate to each other as well as in your overall line confidence.

I'm so happy to see you applied line weight and hatching to each one of your boxes as this is a fantastic way to get free mileage out of the box challenge and you certainly got good value out of it as your line weight is applied really quite nicely at the end and your pressure control seems to have improved significantly.

Your boxes started off with a significant amount of divergence and as you progressed, you tightened this up so that by around box 90 you were consistently producing boxes that look pretty much correct to the naked eye. It's also nice to see a wide amount of variety in the size, shape, orientation, and foreshortening of your boxes as this variety has exposed you to the problem from all different angles.

Now, there are still a few lingering issues with your boxes that you may be aware of, particularly when it comes to the convergence of your parallel lines - in some cases these are converging in pairs rather than together towards the vanishing point. We see this fairly often and it's usually related to the student thinking about their parallel lines mostly in terms of how they relate to one another on any given plane. Instead, as shown in the diagram above, you should be thinking about how all four of those lines relate to one another, even if you haven't drawn them yet - that sounds tough, but consider that all boxes follow the pattern described, wherein the internal (green and orange) lines tend to be pretty similar in angle as they converge towards the vanishing point.

Overall, it seems to me you've gotten quite a bit out of the 250 box challenge and are well positioned to move on.