Good job on finishing this challenge. This one is definitely a tough one for many, so I will do my best to critique your work.

Although I would like to point out convergences and divergences, I believe you are well aware of these mistakes, seeing as you have noted them. I would recommend the Inner Corner method, if you are still having trouble keeping lines from converging/diverging: (https://imgur.com/a/DHlA3Jh). If you draw in the box before doing the inner corner, it will end up becoming more guesswork.

Line confidence was shaky at first, but improved as you drew more boxes.

Boxes 171 to 185 seem to have the lines parallel, and not pointing towards any kind of vanishing point (https://imgur.com/mWLlnYl). It is good that you experimented with dramatic foreshortening at times, like box 245. Even if there were convergences, it is good to keep trying to practice both dramatic and shallow foreshortening of boxes.

I think from here, you can try more variations of orientations of the boxes (these are just for reference, but don't directly copy them): (https://imgur.com/Kqg6uMX). A thing to remember is that the angles in between the initial "Y" must be above 90 degrees, otherwise the box will become distorted. As long as you know these limits, you can orient boxes in any view without worrying about making a mistake.

It's good that you began drawing your boxes more bigger near the end. Overall I think you are on the right track, and it is a good idea to keep trying more boxes occasionally with the critique in mind. Doing 4 - 6 boxes as warmup can be good before starting any assignments/drawing in general.