Grumman-581 writes:

One thing that I noticed that I would at least re-engineer a bit was the
fact that it appears that his hitch plate does not have a backing plate
...

A (smaller) backing plate is only a glorified washer, good only against
shearing through the attachment point. The rest of the bumper will have
failed before that happens, so it adds nothing.

A larger backing plate would be tantamount to replacing the bumper with a
stronger cross-member, and at that point you might as well put on a frame-
mounted hitch instead of using the bumper.