As much as I love Elite in VR, I think it is the worst game for NONE motion sickness related VR issues.
Others in this thread have talked about eye strain (due to resolution etc). I do not think it is that. I play simulators (both driving and flying) for hours in VR without any issues but with Elite I cannot last one hour until my eyes get so bad I have to stop. I think personally it is the constamt huge contrast difference of very light and very dark colours that kills my eyes. I always come away from the game feeling I have been staring directly into a spot light. Obviously as a based space game there is little you can do about that.
For me, Elite is the best VR experience... and sadly the one that alos quickly destroys my eyes!