[css3-regions] region intrinsic size and aspect ratio

Since making something a region (setting 'flow-from') takes over the element's content, it should be reasonable to expect that intrinsic size of the region is calculated similar to that of a replaced element or iframe. Unless of course it is a situation where region is sized to content.

That means that default region size is 300px by 150px, and if either width or height is not specified it gets its respective intrinsic value (because region does not have an intrinsic aspect ratio).

Do you agree?