Starting with your cylinders around arbitrary minor axes, I'm very pleased with your work here. You've been mindful of varying your rate of foreshortening a great deal, and you've taken a lot of care in identifying the minor axes of your ellipses, catching not only the obvious mistakes but even minor discrepancies like in 134 where the minor axis is only slightly off from what you were aiming for. This attentiveness will help you avoid plateauing as you get into the range of being generally "good enough".

To that point - looking at 134 - I did want to quickly caution you against allowing your cylinders to get too parallel - that is, where the side edges stop converging altogether. This is not something I saw you do often, or really much at all, but I did see it a little (139 on the same page for example) where you do start getting into that territory. The reason this is incorrect is explained here in the notes, so be sure to review that section.

Continuing onto your cylinders in boxes, while you started off a little rough (usually when I see students struggling with their boxes initially it suggests that they may not have been as attentive to the importance of including such exercises, line extensions included, into their regular warmup routine), though you did shake off that rust fairly quickly.

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.

For the most part, you did a great job of this, but it was early on that you struggled the most. As I noted above, initially it was with the basic construction of the boxes, but as that got ironed out, I did notice a number of cases where your ellipses weren't quite touching all 4 edges of the plane enclosing them. This would unfortunately render the line extensions somewhat less useful, given that they would no longer relate to the box itself, but rather only the ellipses. Fortunately you corrected this yourself, and after the first 30 of these, you fell into a good pattern of tackling the exercise correctly. From there, I can definitely see a great deal of improvement, which really took off in the last 50 or so.

So! All in all, great work. I'll go ahead and mark this challenge as complete.