Starting with your cylinders around arbitrary minor axes, the verdict is a bit split. You've done a great job in drawing your ellipses with confidence, whilst maintaining accuracy and control and without adding any hesitation or unevenness to the result. You've also done a great job in checking the alignment of your minor axes afterwards, and picked up on fairly small discrepancies which are always good for fighting the risk of plateauing when you get "close" to correct. But there's one critical thing you neglected.

In the assignment section for this challenge, which you'll find screenshotted here, I asked for there to be a healthy variation in the rates of foreshortening across the cylinders for this section. It's important, and I bolded it to try and ensure that students would not miss it. Unfortunately, it seems that you did. Going one step further, it appears that you intentionally tried to avoid any convergences at all for those side edges, effectively putting their governing vanishing points at infinity (as discussed back in Lesson 1), for every cylinder in the set. This is actually incorrect.

While it's unfortunate that you missed the instruction, it does give us an opportunity to talk about why it's incorrect. The vanishing point cannot actually be arbitrarily placed anywhere, at a whim. Rather, we choose how we want the form in question to be oriented in 3D space, which determines where the vanishing point is going to go. The vanishing point can only be at infinity if and when the lines it governs are meant to run perpendicular to the viewer's angle of sight - basically meaning that they're not slanting towards or away from the viewer through the depth of the scene. In other words, it requires a very specific alignment.

Given that, like in the 250 box challenge, we're rotating these forms freely in space, we can pretty much assume that such a a perfect alignment would be so unlikely that we may as well avoid it altogether, having our side edges converge - even if only slightly and gradually - in all of our cylinders.

Continuing onto your cylinders in boxes, these are well done. 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.

You've done a fairly good job of applying the line extensions correctly and consistently. There are a few places where some of your contact point alignments are a little off (as identified here) but by and large you've done well, and your eye for proportions has certainly developed over the set. There is room for continued growth, as is expected, but you should be well equipped for what you need in Lesson 6.

That said, I am going to assign some revisions for that first set, though because your work is generally otherwise well done, they won't be too extensive.