Add a way to opt out of default border width

[CuddleBunny]

It would be great to have a way to opt out of the default border-width: 0 in the config. Under normal circumstances this works well and I think it is a great approach. Once you start using web components and messing around in the shadow DOM however things start to become less favorable. If I have a custom element my-component with internal styles that apply a border:

:host {
  border: 1px solid black;
}

The border element's border will still have a width of 0 because :host is less specific than *. As far as I know there is no way to make :host more specific and the soft override mentioned here will also not work. Thoughts?