I suggest slightly revising the Border tab in the Style panel. Currently, only border and box-shadow are listed under it, and you have to click on the pen icon to access the options. We could save ourselves this extra click if the options were directly available.
Here’s another idea: basically, the width could be linked so that every border width is the same. If you unlink it, the options for each side could be visible below. Figma does this nicely. You could do the same with border radius.
