Hey there, congratulations on making it through the 250 box challenge!

You've made some great strides here. Your line confidence starts off pretty great - though you were correcting your lines quite a bit - but by the end, your pressure control has clearly improved a lot as your lines seem to be a lot more lively. Your control has also improved pretty significantly so well done there - the 250 box challenge is such a fantastic way to practice these skills and push your line confidence forwards.

As for your convergences, you're consistently and correctly applying the line extension method throughout which is great to see. This has helped you identify and tighten up areas of divergence. You seem to have practiced a good mix of shallow and more extreme foreshortening, though you definitely tended to stick more towards the shallower foreshortening, which is okay, since a lot of the boxes we draw will be at this more relatable scale - just don't forget to draw those more extreme ones for when you happen to need them.

Honestly, by the end, a lot of the little mistakes that present themselves in your boxes are pretty much invisible to the naked eye. Naturally we can pick them up a lot easier with extension lines but the boxes themselves look mostly correct. That said, there were a couple of instances where little errors would compound on the final lines or you'd end up with a couple of lines converging in pairs rather than altogether towards the vanishing point as shown in this diagram. Now, I think you're pretty much getting the concept that this diagram demonstrates but to explain it - the silhouette lines of your box sharing a vanishing point (green and orange) will converge at a steeper angle than those on the interior of the box (blue and magenta) - this is a consistent property of perspective and one that you can leverage when drawing your boxes.