For the first 50, your lines are very clean, though I do see some slight arcing and wobbling, like in box 10, box 19, and box 34. I also noticed lines pair off and converge towards two vanishing points, such as box 5, box 23, and box 44.

For the next 50, your lines show improvement, with less wobbling overall. I did see a little arcing here and there, like in box 64 and box 92, but it's very slight. Your convergences also show improvement, though there are still instances of lines pairing off, like box 59, box 73, and box 98.

For the last 150, your lines continue to improve, with fewer instances of arcing and wobbling. There are still a few odd instances, like box 108 and box 179, but as before they're very slight.

Your convergences also show further improvement, but there are more instances of lines pairing off, like box 115, box 164, and box 226. 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.

All said, good work. I'm going to mark this challenge as complete.