Jumping right in with your cylinders around arbitrary minor axes, one thing that immediately does jump out at me is that while this isn't something you're doing consistently, you appear to be drawing the side edges of your cylinders as parallel on the page somewhat often - as we see in cases like 112, 114, 116, 120, 123, 125, and so forth - which is noted in this section of reminders as specifically being incorrect. Seeing this very infrequently could be explained as the result of you trying to achieve very slight convergence, but accidentally ending up with parallel edges, although with this frequency that does not seem to be the case. I also noticed that you'd written "Good?" next to 123, which further confirms that you may have been under the impression that this would be something to aim for.

The rest of your cylinders are generally okay, although your linework also appears to be showing signs of not employing the ghosting method - those signs include an absence of having those start/end points marked out (I can see them on your minor axis lines, although not on the side edges), and those side edges frequently being at least a little hesitant and wobbly (which isn't always immediately noticeable, but is certainly present). Remember that the ghosting method must be used for all of the marks we freehand throughout this course - straight lines, ellipses, curves, etc. - in order to continually reinforce that our first priority is to the confidence of our execution. We achieve this by investing our time into the planning and preparation phases, so that when executing we can simply push through with what we've prepared, but when students start drifting away from this process without realizing it, they tend to do so gradually. First they spend less time in the planning and preparation phases, and in turn they later end up compensating by investing more time into the execution phase, which undermines the methodology as a whole.

So, be sure to reflect upon exactly how you're going about making your marks - we always want to be hyper-intentional with every choice we make when drawing our homework, as this is how we rewire our instincts, so that when we draw outside of the course we're in a better position to apply what we've learned without having to think about it.

Continuing onto the cylinders in boxes, your work here is definitely more consistently better in your execution of the instructions. I'm pleased that you noticed the relevance of the boxes' own proportions, as that is a key aspect of this exercise - though perhaps not in the way you might have thought. 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. That is to say, it's about the box itself, not the cylinder we draw inside of it. We train 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.

As a whole, I can see that you're applying the line extension methodology as instructed, and that you're steadily applying what those line extensions tell you to adjust your proportions accordingly in later attempts. Additionally, your linework does appear to be more confident and consistent here than it was before.

Anyway, I'll go ahead and mark this challenge as complete. As a whole you're on the right track, although do be sure to go through that reminder section I linked earlier, avoid drawing your cylinders' side edges as parallel on the page (or more generally, avoid forcing your vanishing points to infinity if the orientation of those edges in 3D space does not specifically allow for it), and keep an eye on your use of the ghosting method.