I have a use case for Helmet that involves micro-frontends. There is a container app that renders a navbar and hosts within itself other react apps. <HelmetProvider> does not bridge this app boundary, even though the provider rendered in the container app is technically wrapping the hosted app.

Possible workaround:
The container already passes a history object to the hosted app for their instances of React Router to share. If I created a HelmetData object separately, this could be passed to the hosted app. The downside to this is, as it stands, I would need to find a way to distribute this object to pass as a prop to all the instances of the <Helmet> component.