Starting with your cylinders around arbitrary minor axes, there are many things here that I am quite pleased to see:

• You've included a wide variety of rates of foreshortening - despite asking for this specifically, some students still miss it, so I'm weirdly pleased every time a student follows those instructions correctly.

• You're very fastidious in checking the alignment of your ellipses, identifying even fairly small deviations when they are present.

• While you do struggle with drawing confident, smooth ellipses towards the beginning, this does improve over the set. That said, there is still some room for improvement here, so be sure to keep using the ghosting method and engaging your whole arm from the shoulder when executing your ellipses.

One thing that you may not be completely cognizant of at this point, is the importance of keeping the two "shifts" that occur as manifestations of our foreshortening (the shift in scale, where the far end is smaller than the end closer to the viewer, and the shift in degree where the far end is wider than the end closer to the viewer) consistent with one another. That is to say, if we have a more significant scale shift, then we should also have a more significant degree shift to match. Failing to do so would result in a contradiction, where one aspect of our cylinder tells us that what there is a significant portion of the form's length which exists in the "unseen" dimension of depth, whereas the other tells us that what we see is effectively what we get - that the length on the page is all there is.

If we look at some examples - such as 136, we can see very little change in the degree from one end to the other, with a more substantial (although not outright dramatic) shift in scale. 132 is perhaps a clearer example of this issue. This isn't a mistake you make all over, but it's present enough for me to feel that explaining it has been worthwhile.

Continuing onto your cylinders in boxes, I fear this exercise is not wholly complete. 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.

There are two main issues with how you're approaching the line extensions for this part of the challenge - firstly, you only appear to be identifying the minor axis, not any of the contact point lines. Furthermore, the extensions of your minor axes generally appear to be pointing in the opposite direction - what we want is to extend them all the way back, along with the box's own line extensions, so we can identify trends where they're not converging towards the same vanishing points.

I do understand that this particular error checking approach is by no means easy to understand, but it is explained in detail in these notes, as well as in the cylinder challenge video. I recommend you review these, and then give the revisions I've assigned below another shot.