Hello there, I'll try to give you some advice on your boxes:

Things you did well:

• Your lines appear to be fairly straight, almost no wobble to be seen, good job!

• You applied line weight to the sillhoute of your boxes

• Your hatching looks tidy and most of the time you hatched the plane that covers the inner corner which helps make the box'es perspective read better

• You experimented with some extreme foreshortening, which is always good to do in order to see what happens, but improved yourself after that and chose more reasonable vanishing points

What you can work on:

• Many of your lines are parallel or even diverging instead of actually converging. It appears you either chose vanishing points that are so far away that the lines appear parallel or you chose the vanishing point to be super close, so the box appears very distorted. Some boxes have a very reasonable degree of foreshortening :)

• Remember that the degrees in the initial Y should always be >90° so the boxes appear more reasonable

Overall I can see lots of improvement in your drawing boxes skill, specially the last 50 or so are really well done and way better than the first ones! Your boxes look clean and you put the right amount of time constructing each box and checking your lines for convergence with different colored pencils.

I would not worry too much about your concern that the back plane is bigger than the front plane, most of the time it just appears that way and isn't even actually true if you look closer.