GenStage Abstraction for Diverging Pipelines

I am looking for a data processing pipeline abstraction with which I can declaratively setup branching pipelines.
For now I have the following simple pipeline:

P  -->  PCa --> PCb --> C
  '-->  PCc  ---^

P is broadcasting to PCa and PCc.

I was not satisfied with Broadway in this context and modeled the pipeline with GenStage. Even with the simple example there are drawbacks to setting up GenStage. I would like to have everything setup and connected in one place with as little configuration needed outside of the supervisor initialization context.
Something like this:

    name: __MODULE__,
    pipeline: [
      [Producer, [:start_link], :broadcast],

      [PConsA, [:start_link], sub_to: [Producer], max_demand: 1],
      [PConsB, [:start_link], sub_to: [PConsA]],

      [PConsC, :start_link, sub_to: [Producer]],
      [Consumer, :start_link, 
        sub_to: [PConsB, PConsC],
        concurrency: 2,
        rate_limiting: [
            allowed_messages: 1,
            interval: 1_000

Do you know any library I should take a look at?

Did you look at flow: GitHub - dashbitco/flow: Computational parallel flows on top of GenStage?

I did look at Flow and it’s a bit too low-level for my purpose.
There is also ALF which seems to be too high-level :smiley: