Hi there. Welcome to Drawabox. I'll be breaking the critique down section by section, so let's get right to it.

Lines

Your Superimposed lines show some common errors. The biggest of these is wobble. It's not too severe, but noticeable enough. I do note, however, that this is less prevalent in the arcing lines you drew, and mostly ironed out by the time you get to the Ghosted Lines and Ghosted Planes exercises, so good work there. There is also a little more fraying at the origins of your Superimposed lines than the ideal. Remember that, while we're prioritising confident strokes, the starting point of a line is the one place you can take time and be sure of full control, so bear that in mind. Again though, I see improvement as the exercises go on, so good work, and keep at it!

Ellipses

You seem to be very comfortable with curved lines, as the linework on your ellipses shows a lot of confidence. You are properly drawing each one twice through, and they all fit fairly snugly in your tables with little to no overlsp. Good stuff! There are one or two spots in your Ellipses in Planes and Funnels exercises where you lose consistency and confidence though, so these might be good exercises to work into your warmups or regular practice until you feel more comfortable with them. Some of the minor axes in your Funnels exercise are a little off-centre, meaning that they don't cut each ellipse into two symmetrical halves like they should, though the majority are fine. For this issue, I can only recommend taking your time to plot your lines when that kind of precision is required. (Confidence is still key, and it doesn;t need to be perfect, but it the halves should at least look symmetrical at a glance.)

Boxes

Your lines are still fairly confident here, though not always exactly in proportion, especially on the Organic Perspective exercise. Again, it's okay to take all the time you need to plot your lines carefully, and this should help push your results to the next level of quality. You are properly drawing through your boxes, and on the Rough Perspective exercise you have done a satisfactory job keeping the lines either parellel or perpendicular to the horizon line. The prespective is not bad for this stage, and hopefully using the line correction method has given you more of a sense for this, which will help you in future exercises. It would have been nice to see some crosshatching on the appropriate faces in the Rough Perspective and Rotated Boxes exercises, but this is not required. I can see that you tried to give some lines extra weight by going over them again, which is good, but again I'd recommend taking more time to plot those lines as they aren't overlapping enough to create the sense of space you're going for. I's also like to congratulate you on applying fairly consistent rotation to your Rotated Boxes; this is hard and many people struggle on their first attempt.