Firebase performance monitoring with Expo apps? (Can't find variable: IDBIndex)

The Firebase team recently made performance monitoring available for Firebase Web Apps.

As someone using Firebase web with expo, I assume this would be supported in a future release, since Firebase supports authentication without detaching (with AsyncStorage instead of localStorage)

The error I get when initializing Firebase Performance is: “Can’t find variable: IDBIndex”. That refers to an interface for Indexed DB, which is available on browsers.

Is there an expo polyfill for IDBIndex?