Hi @Mikael2
Thank you for your question. I think you’re right to be confused about this—at the moment, the UI doesn’t offer much guidance. This is something I plan to improve in the next version.
First, to answer your question about using Render Preview as a material guide:
In the Prompt tab, generate a prompt and turn on “Include render preview”, then save the prompt.
Now, in the Render view, select the prompt you just created.
Note that you will now see a preview of what is being sent, and under “Summary” you can see the full prompt reflecting that you want to use the render preview as the material guide.
Click Render—and hope for the best 
Regarding your request:
RhinoBanana supports Named Views in the Select View dropdown, which can give you some consistency. I’m not sure if this is what you’re after?
At the moment, the plugin does not work with Layer States or Snapshots. These would allow you to turn different elements on and off, and even apply different materials to the model. In my experience, though, this can become quite confusing once you start editing the model, and maintaining these states as new geometry is added requires a lot of work. Because of that, I’ve never fully embraced these features.
I’m not entirely sure which of these you were hinting at, or if I’ve misunderstood your request.
I am, however, considering introducing a batch render feature in the future, so you can render multiple views in one go.
I hope this answers your questions.
Best,
Johan