I think your best option is to use a custom login page. What you can do is create a default homepage microflow that is enabled for normal users and anonymous users.
The microflow starts with the deeplinkhome microflow. If the boolean from this flow is true you stop the flow. If it is false you should check if the user is anonymous($currentuser/isanonymous) if it is you should redirect it to your custom login page, if it is not anonymous this means it is a logged in user and you should redirect it to your homepage.
For your custom login page you can use the Loginform widget.
In the deeplink module you create a link like http://localhost:8080/test
When you are not logged in and call this url the default homepage microflow is started for a anonymous user and through the deeplink the user is redirceted to your specific microflow.
Hope this helps you.