Found a possible fix for dlss 4.5 grass or hair like structure shimmering.
For example i used dlss mod in Elden Ring, i saw very bad shimmering while ray tracing max and dlss m with quality option, so after trying out many option i found out motion blur is the issue, after turning it off it was 98 percent gone. But after checking the same thing for Black myth wukong where there are hair like structure everywhere, I found out main culprit was sharpening, anti-aliasing and shadow quality, i used preset m with quality 66%, so what i changed was turning shadow quality from high to very_high(tried cinematic it also had that continuous shimmering) then turned anti-aliasing to low to be honest with you this barely changed anything but game looked better than before with changing sharpening from 4 to 2.
i was using 1080p monitor so shimmering would be far higher than 4k.
conclusion: so I think for any game with ray-tracing on, turn of motion-blur and shadow quality to maximum though I should say check it yourself which shadow settings fix yours.