Hi ssg,
Welcome to the forum!
I have my WEPS for over two and a half years now and my vise also has a very small indentation. I guess it started already after a few knives… it is quite visible, since the black paint from the vise is removed.
But really, this is only cosmetic, it doesn’t affect the operation the slightest. There were people who found it annoying and come up with innovative solutions, like metal plates where the bottom screw touches the vise. And I think the latest version of the vise also comes with a piece of metal there. But it’s not necessary.
Just to be sure, when you clamp a knife, first fix the top screw and then the bottom one.
Have fun!