Expo currently supports the Facebook Login function from the Facebook SDK. However, it does not support the SDK's basic function of tracking app installs on its own.
To be able to track app installs, the SDK simply has to triggered in the app when being used. It doesn't require specific code to be added for tracking installs like the Facebook Login function.
Please include the ability to use the Facebook SDK for tracking app installs. Tracking installs can be used for the purpose of tracking the results of Facebook ad campaigns.