Starting with your cylinders around arbtirary minor axes, you've done a good job of varying your rates of foreshortening, and of checking your minor axis alignment. In this latter area, I'm especially pleased to see that you were always attentive to finding the true minor axis, even when you were only a little bit off. It's easy to slip into the habit of saying "that's close enough, it's correct", which can lead to us plateauing in our growth when we get to the stage of being "good enough".

One issue I did notice however is that you appear to not be drawing through your ellipses two full times before lifting your pen as is required for all the ellipses you freehand throughout this course (as noted in Lesson 1). You're still doing fairly well when it comes to drawing those ellipses confidently, although drawing through your ellipses will continue to help push you further in this direction, as you still do have cases where you're hesitating enough to add some unevenness to the ellipses' shapes.

Continuing onto your cylinders in boxes, you've done a solid 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.

By checking the line extensions for your ellipses as consistently and thoroughly as you have, you've given yourself ample information on which to judge where your approach is working well, and where it might need to be adjusted to yield better results. In turn you've been able to apply this on the next page, and while it wasn't necessarily a conscious goal, this does ultimately result in better judgment for those box proportions.

One issue that I believe you're already aware of, but that I still wanted to call it out. In cases like 228, where the minor axis of the far ellipse is so far off that it appears to align with the vanishing point above, it can be easy to mistake this for being correct. The colour-coding of your lines helps a lot here, which is why I expect you understand this to be a mistake, but I wanted to call it out anyway. This generally happens when we accidentally make our box really narrow.

As it stands, you've made solid progress, and should be well equipped to tackle the next lesson. I'll go ahead and mark this challenge as complete.