Starting with your cylinders around arbitrary minor axes, overall you're handling these quite well, but there are a number of cases that suggested you may not have been as aware of some of the points raised in the instructions as you could be. Specifically, these would be cases where the side edges of your cylinders were kept parallel on the page, so like 50, 61, 67, 116, 134, and 141. It's not entirely clear whether the intent was to have them converge ever so slightly (and there are others which are close to running parallel on the page, but where I feel this intent is clearer), or if these were cases where you opted to force that vanishing point to infinity. If it's the latter, note these reminders from the instructions, and be sure to avoid forcing any vanishing points to infinity for this exercise, or any where we're generally rotating our forms randomly in space. Conversely, if your intent was to have them converge, be sure to exaggerate the convergence just a little bit more.

Aside from that, your work on this section is looking solid - you've got lots of variation in orientations, you're clearly mindful of the shifts in scale and degree between the ellipses on either end of your cylinders, and you've done a great job of checking each and every ellipse's minor axis alignment with care.

Carrying onto your cylinders in boxes, your work here is similarly well done, and I'm very pleased to see how stringently you stuck to the procedure for applying those line extensions. 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.

In applying that methodology for analysis as fastidiously and mindfully as you did, you ensured that you were armed with a good grasp of how your approach related to the results it produced, giving you ample information with which to shift your approach and gradually refine the outcome. You should be well equipped in your understanding of these proportional relationships to continue forward, so I'll go ahead and mark this challenge as complete.