Accessing UI Theme Designer on CF without a Portal service instance

I followed most of the documentation to access a UI Theme Designer instance on CF.

I say 'most', because there is one prerequisite that I can't figure out why and how to set this up:

A PaaS Portal setup is enabled when you have added a launchpad module to the app you develop. The launchpad serves as a home page to access the UI modules (apps) in the application.

From Developer PaaS Scenario on SAP Help

I have setup created an instance of the service that is bound to my approuter. Accessing <approuterhost>/comsapuitheming.themedesigner/ results in the following error:

Cannot GET /comsapuitheming.themedesigner/

I assume this has to do something with the prerequisite that I haven't setup yet.

I have two questions that come to mind:

1. Does UI Theme Designer require a Portal service subscription (including the user licenses for end users accessing the apps)
2. What is the solution for standalone apps, that are not accessed via the Portal service?

P.S. @ SAP, please provide a Tag for "UI Theme Designer for SAP BTP, CF environment"..