Hi there again, Pixex!
Just out of curiosity, have you considered using one of those Iray cloud servers to run your renders outside of your laptop?
F95Zone is giving access to community iray cloud servers for free to small Game Developers that are lacking ideal hardware for their work. This may be helpful.
If you want to learn more, here's the thread:
https://f95zone.to/threads/free-community-render-service-iray-server.66967/
On another note, if you want, I can send you the node script I wrote to run the de-noiser over the chapter 1 files back in March. I'm offering this in case you want to be able to batch de-noise pics for chapter 2 as well.
PS: That render for chapter 2 looks sleek!
Best of luck <3