TextAreaFieldWidget rows/cols and support in the field editor?

The Text and the TextAreaFieldWidget support setting the number of cols and rows on the supermodel XML level.

    <field name="foo" type="zope.schema.Text">
      <form:widget type="z3c.form.browser.textarea.TextAreaFieldWidget">
        <rows>20</rows>
        <cols>50</cols>
      </form:widget>
    </field>

Would it be hard to support both settings in the field editor?