You might want to try out some community mods specifically for the propellers:
There are two problems with the propellers: the 1st one is everything behind wobbles because of motion smoothing (the mods help curing this), the 2nd one is TAA is not coping well with the moving image either (the mods help curing this a little).
The reason for the 2nd one is because the algorithm is based on measuring pixel displacement from one frame to the other so that it can estimate what pixels to “blend”, eliminating the edges aliasing (to keep it simple). You can actually see the TAA buffer in dev mode, there is an option for this in the view menu.
The problem is the same algorithm will also compute a motion vector for pixels moving not because of the camera changes, but because they are actually moving pixels (cars, props, windmills, etc…) and in this case, they don’t exclude these moving pixels from the motion vector which is trying to just smooth everything out.
This is highly annoying with cars in VR (see explanation and video):
TAA is transforming road traffic into ghosts (self-cancelling moving pixels)