With the new authentication implementation you shouldn't need to login multiple times (unless you are loading contents from multiple portals). By design, you will also be prompted to login (again) when you open the editor and/or press play. If you are having issues with multiple logins other than these cases, please let us know.
If you want to keep using pregenerated tokens, you should be able to use them as the api key. If you want to load different layers with different tokens/keys, you would have to add those layers through api.
Another option that you have is to implement your own login handler for the play mode and standalone builds based on our sample code in `SampleOAuthUserLoginPromptHandler` and insert the pregenerated code as the server response in there. To register the custom handler with the authentication manager, write your own script or modify the `SampleAuthenticationHandlerInitializer` component.
