This is my personal project, which I did in my spare time from work. I used Ornatrix in Maya to create the hair. Then I exported everything in Ox Alembic format and imported it into Unreal Engine 4.26.2 using the Groom Plugin.
Haircount for this video - 120K and 70 CV points per guide. I didn't use LODs for this scene.
I'll show you soon how to transfer it to Metahuman.
I still don't like how DoF works on hair and what happens with sampling. I am trying to fix this issue with Epic Games.
I created a topic on my blog. As will be the answer from them, I will add it there.
By the way, in the same place - you can see the render settings.