[css-text-decor] addition of thin | medium | thick length values?

[BillGoldstein]

https://www.w3.org/TR/css-text-decor-4/#text-decoration-width-property
Add thin | medium | thick lengths to:
text-decoration-width
text-underline-width
text-overline-width
text-strikethrough-width
similar to border widths.
Possibly with default for values in ems rather than px.

[fantasai]

@BillGoldstein What's the use case? Don't most designers who want to set the width want more control than that?