I'm using localforage to persist the state for a react app. However, It's still not perfect. Because in safari private mode, the state will be removed after refreshing the page. What is the fallback for this situation?
The whole point of Private/Incognito/etc mode is that sites are not able to persist data beyond the browsing session, and therefore (1) leave a trace on the user's device that the site was accessed and (2) allow the site or third party content to recognize and track visitors.
If there were such a mechanism it would be considered a serious privacy bug by the browser vendor and fixed promptly.