I have used milk crates for a long time on most of my rides. I placed one on my Transport on the rear as I can always use a little more cargo space. However, I realized that, when traveling empty, it was just heavy enough to be a little top-heavy and would cause a little rear wobble after hitting a good size bump.
So, the solution was to cut about three quarters of the weight off of it. I have been riding for about a week with it like this and the wobble is gone. Hopefully, it will not return until I happen to load something a bit too high inside.
The area is still about the same for carrying things. But the extra plastic that was taken away, along with the height, is gone.
You can see the difference in the attached photo.....