First my rig, it's not a potato (8600k at 5ghz, 32MB RAM at 3600mhz and a 3080Ti). I have the x64 FSR mod running and that was/is a huge benefit, so FPS in VR is smooth as silk. But no matter what combo of settings I've tried so far I can't get rid of flickering shadows and sparkly/shimmering fences and track in the distance. Until I turned off the shadows completely. What is it they can't get right with that?
This is SMS' implementation at fault. It's not that Reiza can't improve it but rather that someone would need to do some serious studying/learning about graphics programming to improve things (or hire someone who can), but with the current development program and priorities, I think these changes will have to wait longer. As far as I can understand, since these issues aren't relevant to gameplay (and seen more as an immersion issue) they can be easily pushed down the priority queue. This doesn't mean it won't ever be addressed (there were already minor improvements made within the technical abilities of the team), but simply that once the opportunity is there it'll be studied.
I just turn shadows off. The tree shadows on track are so bad, and turning off shadows makes them go away. Still get a little shadowing under the car, so for me it's acceptable with them off. With shadows on, I simply cannot stand looking at those tree shadows.
I play in overcast or cloudy conditions to reduce the hard edges on the shadows. I still hold hope Reiza will fix shadows.
Shadows and anti aliasing have been poor in the madness engine for many many years, and I think @Shriukan is right that no one within Reiza right now can fix these graphics issues, otherwise they would have already have done so.