Starting with your cylinders around arbitrary minor axes, I have to admit - for the first 100, my heart sank. Where the assignment did specifically say to vary your rate of foreshortening, you had neglected to do so. Taking it further, you appeared to be consciously and intentionally forcing your cylinders' side edges to remain parallel on the page, effectively forcing the vanishing point that governs them to infinity. This doesn't merely deviate from what was asked, it actually gets into the territory of being incorrect, as far as the rules of perspective go.

Our vanishing points go to infinity, resulting in lines that are parallel on the page itself, only when that set of lines is oriented in such a way that it runs perpendicularly to the viewer's angle of sight - basically running right across their field of view without slanting towards or away from them through the depth of the scene. Given that this challenge, like the box challenge, has us rotating our forms freely throughout the set, this would be incorrect. The likelihood of such random rotations being perfectly aligned in such a way would be minimal at best, so we're really better off always incorporating some convergence to those side edges, rather than making them run perfectly parallel on the page.

Fortunately you appear to have caught this mistake, and a little past the 100 mark, you remedied this and started incorporating more foreshortening into the mix. Not a ton, as it still remained fairly shallow in most cases, but this does make the difference between me simply warning you of your initial mistake, and me requiring that section to be redone. That said, it does bring an additional point for me to call out.

The reason I ask students to vary their rates of foreshortening is because it gives me an opportunity to check if the student has noticed the relationship between the shift in the scale from one end to the other (where the far end gets smaller overall), and the shift in degree (where the far end gets wider). It's something I don't address in the material because some students pick up on it more naturally, and allowing them to do so will make it stick better.

Basically, the relationship between these two "shifts" is that given that they represent the same thing - the rate of foreshortening, or in other words just how much of the form's length exists right there on the page, and how much exists in the "unseen" dimension of depth - and therefore they must operate in tandem, at roughly the same rate. I can see some suggestions that you're beginning to pick up on this, although there are other cases that suggest that it's only a tentative thing. For example, 135 has the far end get noticeably smaller, but still maintains the same overall degree. 137 is better, with the far end getting more visibly wider, but could be exaggerated further.

So! Just be sure to keep those points in mind going forward, and count your lucky stars for having caught the absence of foreshortening when you did.

Continuing onto your cylinders in boxes, your work here is considerably more consistent, and as such, you've largely done a good job. This exercise is really all about helping develop students' understanding of how to construct boxes which feature two opposite faces which are proportionally square, regardless of how the form is oriented in space. We do this not by memorizing every possible configuration, but rather by continuing to develop your subconscious understanding of space through repetition, and through analysis (by way of the line extensions).

Where the box challenge's line extensions helped to develop a stronger sense of how to achieve more consistent convergences in our lines, here we add three more lines for each ellipse: the minor axis, and the two contact point lines. In checking how far off these are from converging towards the box's own vanishing points, we can see how far off we were from having the ellipse represent a circle in 3D space, and in turn how far off we were from having the plane that encloses it from representing a square.

In applying the line extensions correctly - and more importantly, thoroughly - you've generally done a good job of learning from past attempts and improving over the set, ultimately developing that internal understanding of how to shift your proportions while drawing your boxes, regardless of their orientation in space. This is of course something you'll be able to continue improving upon, but as it stands, what you've developed thus far should help you out as you move into Lesson 6.

So! I'll go ahead and mark this challenge as complete.