I'm sure his point was that motion resolution is absolutely destroyed by camera motion blur. When you move the camera all the pretty bells and whistles and higher pixel count you get with resolution mode are no longer visible since the image is blurred.
And yet even within the motion blur, it's still not shimmering to the point it looks like any and all foliage is sparkling!
Having said that, if Guerrilla releases a patch that tweaks the AA to remove shimmering, I'll happily jump to Performance mode. I don't think the resolution downgrade is nearly as awful as the edge issues.
Having played HZD on a 3090, Quality mode in Forbidden West looks like an improvement while (right now) Performance looks like a downgrade, and I think the 30fps option plays well enough that I never feel like I'm fighting the frame rate.