You should use World Position Offset Disable Distance for your tress because in this moment, the virtual shadow on your scene is calculated every frame because of WPO. Also, the nanite trees are instances, no?
PS: I ran some performance tests using World Position Offset Disable Distance in a scene using Lumen and VSM. Even with heavily forced LODs (which clearly don’t look as good as Nanite meshes), you can still gain performance by using Nanite combined with world position offset disabled. The biggest challenge when working with Nanite and VSM is handling meshes that rely on WPO effects. If your world consists entirely of trees using WPO effect, then sure, using Nanite might not be the best approach. However, it’s not accurate to conclude, as stated in your video, that “Nanite can’t handle open-world games.” Try creating a city scene instead, and you might find yourself saying, “As you can see, LODs can’t handle open-world games.”