Wait - we&#x27;re talking about the result of the combination?<p>If you follow a &#x27;get started with redux&#x27; thing and end up with a root reducer that uses combineReducers: You&#x27;re talking about the outermost &#x27;state&#x27; object? Because any reducer that you write can certainly accept&#x2F;understand&#x2F;return immutables, right?<p>If I picked that up correctly: Is that a problem for a single combineReducers at the root? Because if all the properties of that thing are immutable, wouldn&#x27;t you get the cheap identity based comparison benefits whenever you pass on props.foo in your store-aware component?