The TECH DEMO works fine for a tech demo with user freedom. The main issue I've seen as stuttering that did not come from the missing on pc feature "directstorage" was the physics engine and I'll be be honest the car damage in it looks pretty dope, The deno uses heavily new systems are really new in comparison. Nanite which even if it was mentioned it can remove the poly cap in scenes still has a hit on performance and it is a storage based approach to dynamic detail, lumen is ray tracing under the hood that uses a special type of geometry called signed distance fields, which based on count in range of the global illumination is so it slows down based on the objects in the scene, world partitioner a new open world system that I can't give too much details but all 3 are really reliant on getting the mesh data out from an ssd in speed currently too slow to work properly on pc. The issue with chaos is that having a physics based system to work in all the new directions they've went with is complicated and will take a fair bit of time. The other issue people don't probably think is heavy are the npcs, they actually have strand based hair not hair card which is cheaper but gives less physics to the hair and is harder to make hair that looks good, which are in their lowest lod, so that hits performance like a beast on the gpu