For the first 50, your lines are very clean overall. I only saw a few instances of arcing, like like box 10 and box 26. Your convergences show decent accuracy, though I did notice some lines pair off and converge towards two vanishing points, like box 5's blue lines, box 34's green lines, and box 49's blue lines.

For the next 50, your lines show improvement. I saw very little arcing in this set. Your convergences also show improvement, though I did notice a few more instances of lines pairing off, like box 59, box 70, and box 90.

For the last 150, your lines remain consistently clean and even, with minimal arcing throughout the rest of the set, demonstrating good technique and consistency. Your convergences also continue to improve. However, there are still instances of lines pairing off, like box 120, box 180, and box 243. In these boxes, the inner lines (green and orange in this diagram) diverge instead of converging at the vanishing point. Keeping in mind the angles of neighboring lines can help when planning the box's construction.

As an aside, box 203 is missing some line extensions. It's not a major issue since it didn't happen often, but I want to point it out for future reference.

All said, you did very well. I'm going to mark this challenge as complete.