Scale attribute

I’ve encountered a couple of questions from customers this week, both related to the scale attribute: 1: @scale has no restrictions on values when used on <image> but it does on <fig> and <codeblock>.
Is there a specific reason why it is restricted in some cases and unrestricted in others?
2: In DITA 2.0, the <video> element allows @height and @width, but not @scale.
Would it be possible to add a scale attribute to that element?
Thanks, Dawn