Ability to drag new components inside instances

So ive noticed that currently we can create an auto layout of a component for example a card. Save it as a component. But if we needed something a bit more bespoke, for example bringing in child component such as a table which isnt built in that varient of the card we would need to detach the card instance > bring in the new component.

Ideally you would have the functionality of introducing an editable area in the master component where new componets can dragged inside. Almost a bit like an iframe where your instance will still be undetached but a specific area chosen in the master you have the ability to drag in child components.