You might want to reopen your Zendesk ticket because what I’m documenting above has nothing to do at all with Pimax.
I’m documenting FS2020 object culling algorithm is wrongly culling objects prior they reach the culling planes to the side when setting SteamVR to 50% FOV with an Index.
I’d suspect the same algorithm isn’t culling objects after they reach the culling planes to the side when using more than SeamVR 90% FOV with an Index, therefore leading to poorer performance processing necessary objects.
PS: Actually other similar problems manifest themselves much closer right in the cockpit. This might have nothing to do with frustum culling itself, but it might be related to more general LOD/culling problems:
LOD Problems - Distances revisited - #38 by CptLucky8
TL;DR: object visibility depends also on the viewing angle, it might be visible at 45 deg to the side and disappear when viewed directly at, while being at the same relative distance to the eye in both cases.