Cool. 
Where did he mention agx-emulsion? Not finding anything on his channel.
Interesting! A Python project. I wonder how difficult it would be to build an .AppImage.
I know this isn’t a darktable thread, but sadly the LUT 3D module in darktable rather limited. But perhaps it would be possible to create LUTs in Spectral Film LUT that could be used in darktable?
Also, the grain module is monochrome only in darktable and grain gets applied pre-interpolation.