That's the one! Fantastic work btw, the mod works brilliantly, and does exactly what I want it to.
Interesting to hear vkBasalt can't do the same thing, but it makes sense that it'd be purely post-process, and your results speak for themselves that you're doing something a little more integrated.
Obviously I'd love either native support (Hollow Knight got native HDR with the Xbox release, IIRC), or a proper mod, but I don't necessarily expect either from yourself necessarily (you've done fantastic work, which does run on Linux via Proton anyways), and I don't expect either for at least a year or so, as the modding community sink their teeth into the game proper.
Hopefully next year I can play a Silksong archipelago randomizer with a dedicated HDR patch and some QoL tweaks for faster runs, all on the native Linux version!