So in my setup at the moment I have an RTX2070s, a Phanteks PH-TC14PE CPU cooler and the whole thing in a Coolermaster h500m case.

For me it didn't fit because of the PSU cover, but I was able to cut a suitable lock in the cover and move the whole thing down one slot.

Now it fits exactly to the millimetre, but a 3090 would no longer fit in my case.

I can't tell you for your specific case that it will fit, but I have a be quiet pure rock CPU cooler and it should be the same size as yours and my graphics card is an ASUS ROG Strix GTX 1070 Ti, which according to Digitec is 0.6 cm smaller than yours in width and it just fits underneath. I guess it could fit, but don't take my word for it.