Well I’ve just had a first go at comparison of settings in Elite Dangerous on my 8700K with GTX 1080 OC
ED - Combat Training Mission
ED Settings: Quality VR Medium
Version = .84, RenderQuality=1, FOV=Normal, HAM=Enabled, CWPP=Enabled
Video=100% and App Resolution=100%
Resolution=4622x3949 per eye
FPS = 45
Video=50% and App Resolution=100%
Resolution=3268x2792 per eye
FPS = 63
Video=40% and App Resolution=100%
Resolution=2923x2498 per eye
FPS = 78
Video=28% (recommended in SteamVR) and App Resolution=100%
Resolution=2446x2090 per eye
FPS = 90
Surprisingly ALL modes felt playable, the highest 100% setting giving 45fps the movement was noticeably less smooth, especially on the target ship.
At the recommended setting (28% in SteamVR), it still looked good but you could just start to see text slightly degraded, slightly more jaggies!
Obviously, there is plenty more that can be tweaked, this is just a first impression and attempt at comparing settings to see how ED works out on my PC and maybe a reference for others.