@Franz_H you can extend component’s properties using the config-ext.json file we provide when overriding the component in the SDK.
In fact, I would say this is preferred approach than hard coding the run time experience. The more you make configurable in design time the more flexible your component and configurations will be (aka future proof).
The team run through some examples in our DX Component webinar. We had 2 sessions and two different people present their components, so I would suggest watching both, we provide a full breakdown and recordings on our Summary Post.
Design time of some custom DX Components
