Thanks for the feedback, in regards to the boxes, you can see the same wooble that you mention in the line excersice and even some doble line product of the miss jugde of the orientation of the line, remember that there is one excercise that ask you to use a ruler to make the first face of the boxes with the ruler and then, make the lines that goes to the banishing point, that it maybe the one that you say that looks make with ruler