I've already checked the different blu-ray releases of Suspiria for DJ and I say it's no use. They all look too bad and have too much crushed blacks and whites to be restored.

As for that project that Jetrell Fo linked, judging by the screenshot comparison the so called restored and preserved version is suffering from very heavy aliasing, even worse than the GOUT. Maybe they tried to upscale a DVD version and merge it with a blu-ray or something? It sure looks bad in those screens anyway.

Now let's move the Suspiria discussion to that thread instead.