There was something about LUTs being an inappropriate tool in this area when Filmic was being introduced, wasn’t there? Or at least, I remember some raw tempers about LUTs, but I don’t remember the details and couldn’t follow the math. It’s been years now (wow) and I don’t know how to easily find the relevant discussions.
On a different note, speaking of film emulations and data sheets, have you been following the work over on Spektrafilm, specifically the technical discussion here? They’ve been doing some amazing work for the last several months, and projects like ART and vkdt have incorporated a lot of it.