I found out that it is possible to force specific model LODs via DevMode, so I did some more investigation on the reflectivity of the Gherkin model.
LOD4 - A very basic model stripped of all details, but cubemap reflections are properly applied on its surface, giving it an accurate look from afar.
LOD3 - The model gains screen-space reflections (which are visible on the sides only), but it completely loses cubemap reflections!
LOD2 - Only some minor detail additions at the top, not much difference.
LOD1 - The model gains a lot more detail, however it still looks very dark and it is bugged, some textures and the screen-space reflections are constantly flickering. Not good!
LOD0 - The model at its highest detail, looks fairly accurate but its colours are still somewhat off.
Looking at it more closely, we can see that cubemap reflections work properly, unlike LOD3 and LOD2, however they are too dark. The Gherkin is much brighter in real life, like LOD4.
But looking even more closely, we can see that some textures appear to be missing. As a result, we can literally see through the model between the glass windows.
There is definitely a lot of work needed to make the model look accurate to real life and smooth out the LOD transitions. It kind of sticks out like a sore thumb compared to all the other shiny buildings in the area so hopefully they’ll look at it.