Our endorsed package READMEs all have text along the lines of this from path_provider_android:

This package is endorsed, which means you can simply use path_provider normally. This package will be automatically included in your app when you do.

Some go even further, like in_app_purchase_storekit:

This package has been endorsed, meaning that you only need to add in_app_purchase as a dependency in your pubspec.yaml. This package will be automatically included in your app when you do.

This advice works in the simple case, but is confusing/misleading when people are accessing platform-specific API extensions (see dart-lang/sdk#59045 for example). We should update all of the boilerplate to something a little more nuanced, which distinguishes between using just the app-facing package's APIs and using platform implementation package extensions, with instructions for each. (The latter won't apply to all plugins, but we can phrase it generically enough that it could also cover the rare-but-possible case of using a package directly which could apply to any plugin.)