For the first 50, your lines are clean overall, with only a little wobbling present throughout the set. Your convergences also show good accuracy, though I did see some lines pair off and converge towards two vanishing points, like in box 8's green lines, box 29's green lines, and box 47's red lines.

For the next 50, your lines show improvement, with reduced wobbling overall. Your convergences also show improvement in accuracy, though there are a few more instances of lines pairing off, like box 54's blue lines, box 78's red lines, and box 97's red lines.

For the last 150, your lines continue to improve, with wobbling further reduced. While a little remains present throughout the challenge, it's not severe enough to be a problem and you're already on the right track. Your convergences also continue to improve, though there are still instances of lines pairing off, like in box 110's green lines, box 177's blue lines, and box 238's blue lines. 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 124 is missing some line extensions. Box 27 also has some lines extended in the wrong direction. 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.