During my everyday work with Jakarta Server Faces I test as much as possible just below the UI (Subcutaneous Test) - meaning without Arqillian Graphene/Drone/Selenium - by simply calling the backing bean's method in a usual Arquillian Integration Test.

In this case the scope doesn't matter for the test. Hence simply override it via @Specializes or @Alternative. I rather recommend the latter one because a specialized bean's parent needs to be part of the Arquillian @Deployment, leading to unnessecary more code.

Via this way you use official Jakarta and Arquillian Framework tooling.