Experimenting with anonymous vs logged in users.

Hi.

We operate in a diverse ecosystem, where we have many anonymous users and logged in users. 

We want to perform experimentation on both of those user basis', we have the concept of DeviceId which is persistent across installs on Android but not for iOS.

Once a user logs in we have a GUID for the user. We've set up different splits and traffic types such as Device and User.

How do you technical setup this up on the mobile SDKs where you have two different MATCHING_KEY's?