Best 20 scores submitted in a week
First of all, it is interesting to see how people progress during the contest. In Dom Perignon II we saw Faith Perez entering at 42 wpm and ending at 80+ a few weeks later. So you should not hesitate to submit better entries.
As to the weekly awards, we are going to award them to the 20 best entries submitted during the week. This means that you can get another award in a later week by improving your score. Your question made me realize that we may not have worked out all possibilities but if needed wee may "invent" additional weekly awards.