Thanks, Vouka,
Andrea, the added grain definitely makes the image look sharper. However, I would advise you to use real 35mm film grain scans, like Crumblepop 35mm grain. This grain pattern looks a bit like noise. We need only those scenes where the open matte gains good amt of info at the vertical space. Then we could construct an IMAX version.
Any action-oriented scenes look open-matte in this, like the battle in the sky with death eaters early in the film?