How to use FrozenRenderSceneTag

RenderMeshSystemV2 super slow or super fast and it seems adding FrozenRenderSceneTag is absolutely crucial to use it, yet I can't seem to find any info on FrozenRenderSceneTag.
Should I just be adding

new FrozenRenderSceneTag() { SectionIndex =1}

to whatever I want to draw fast?
There is that

Hash128 SceneGUID

that I've have no idea how to use and

int SectionIndex

that I just set to 1. Also

int HasStreamedLOD

is a int rather than a boolean, so I bet it is doing more than just telling if the mesh has steaming lod or not.
So what are those and what's the correct way of using them?

 

Sorry for necroing this, but a year later I still don't know how to correctly use this.

 

I don't think you should be using it directly. It's added automatically for you during conversion from the
FrozenStaticRendererSystem

You can use StaticOptimizeEntity to mark an entity static.

 

If I understand correctly, V2 doesn't to use StaticOptimizeEntity, but does use FrozenStaticRenderSceneTag.
FrozenStaticRenderSceneTag can be used to upload a RenderMesh once to GPU.
Not sure how the SectionIndex value is used tho.