Maybe you're missing the useDefaultViewWidth and useDefaultViewHeight properties? If they are checked, the object view will be made to fit the size of the view as it is defined, otherwise the contents of that view will be sized to fit the embedded view object.
I myself tend to use "auto" position basis and flex layouts instead of fixed pixel sizes and coordinate containers. I'm not sure how a coordinate container acts with regard to those "useDefaultView" properties when used as an embedded view. A coordinate container will resize nicely to fit within an embedded view, but only when set to "percent" mode.