If I could create a component, and define a div as the child-container, then I could use that component, and nest inside of it other elements in a design.

I understand now I can set a property for a component that accepts rich text, and that's awesome, but it's not quite what I'm hoping to do.

With this feature, it would unlock a whole new set of powerful possibilities with components. For example, I could create a big component which is the website main template (includes a header, body, and footer). The body could have an empty div which is designated as the child-container. Then, in my design, I'd throw in an instance of the template component, and then I could put whatever elements I want inside the component (inside the main body of the template).

Basically, this would mimic the functionality of react's children:
<Template>
{any_children_elements_or_compoments}
</Template>