The impeccable 4K exr add-noise workflow?

Hi, i’m looking into pybox to see if it could be useful for degraining and regraining (neatVideo + dasgrain).
Anyone have any idea on how to see within nuke interface the “input node” coming from flame?
Both neat and dasgrain need to sample an image and from flame is not coming out anything visible within flame.
Right now i’m rendering out plates from flame just to have a visible plate in nuke for sampling grain and is not ideal.