I have found storybook to be very beneficial in working on a large react application. This allows taking a component and rendering it independently of the application.
This allows getting the component into all of the possible states without needing to fake the rest of the world.
An error form can display all possible errors, which makes checking things far easier.
The last problem I need to solve is to ensure that the component is styled in tje same manner. Hence the above link. I hope to use this to ensure that Storybook has a high fidelity match to the app, as currently I am missing the exact fonts used.