Starting with your cylinders around arbitrary minor axes, overall you've done a decent job here. Your ellipses are confidently drawn, and while with more mileage and perhaps a little more time invested into the planning/preparation phases of the ghosting method, they should continue to tighten up (although they're coming along fairly well already). You're also taking the time to check your alignments thoroughly after the fact, which is good to see, and they certainly do improve over the set.

One issue I did notice though is that you don't appear to have followed all the instructions entirely. Specifically, even though in the homework assignment section I mention, in bold, that you should be varying the rate of foreshortening across your cylinders, you've basically just stuck to fairly shallow foreshortening, with minimal (and sometimes no) shift in overall scale and in degree from one end to the other.

There are a few cases where you pushed the foreshortening a little farther, like the top left of this page, and it does show that you appear to understand that the harder you push the shift in scale, the more you should also push the shift in degree (because they're tied to one another, and should be consistent) - so I'm glad to see that. Of course, I don't really have any way of seeing if that is actually a conscious understanding you have of how foreshortening works, or if it was just a lucky fluke.

Be sure to read the instructions for any exercise in full, so that I'm given adequate information to assess these things.

Moving onto your cylinders in boxes, your work here is coming along well. You noticed that the proportions of the box itself are what govern the success of the cylinder placed within it, and you're spot on with that observation. This exercise is actually more about training students to develop their instincts in terms of constructing boxes with the correct proportions. That is, a pair of opposite faces that are "square" in 3D space. We develop this by using the ellipses in the way we use the original line extensions from the box challenge. Those ellipses have their own lines, and the closer they are to aligning with the box's vanishing points, the closer the ellipses are to representing circles in 3D space. If this is the case, then the plane enclosing said ellipse would also represent a square in 3D space.

I can see that you have developed a good grasp on how to achieve proportions that are closer and closer to square, and this should help you out a fair bit throughout the next lesson. So, I'll go ahead and mark this challenge as complete.