We do not currently ship with a Stingray PBS shader workflow. There is options to make your own, however.
The workflows we have set are typically for production renderers, and Stingray PBS is sort of superseded by Arnold/aiStandardSurface or the new StandardSurface shader as the main viewport shaders for Maya.
The Maya LT version of the plugin does currently have Stingray PBS as an option, as that's basically the only shader for it. However, the workflow part of the Maya LT plugin is much more limited.