As Handoff is still in Alpha stage, some of the features needed to harness the full power of components are not yet available. An overview of features that are planned:

• Overriding elements – For example a Card component that needs a unique image every time you reuse it. To developers, this pattern is known as 'slots' or 'render props'.
• Overriding styles – For example a Button that may appear in a number of variants, typically Primary, Secondary. Or 'state' variants like Error or Warning. Often known as 'props' or 'variants'.
• Events – Developers need a way to hook up user interactions to their own code, known as event bindings.

Also check out: Roadmap