Nobara ships the required kernel patches and userspace utilities to take advantage of PixelCluster's work as blogged here.
https://pixelcluster.github.io/VRAM-Mgmt-fixed/
To install on KDE Plasma:
sudo dnf in dmemcg-booster plasma-foreground-booster-dmemcg
If you're not on KDE Plasma, you can skip the plasma-foreground-booster-dmemcg package but you HAVE to use Gamescope to take advantage of it.