dr-film's README still described one 32³ lookup that took a negative
through the print and the paper, with the sliders' values baked into
it. Since 6b99f67 nothing a slider moves is baked: the curves are one
row per development time the datasheet measures and push interpolates
between them, a print is two lookups split at the paper's log exposure
with the enlarger's exposure added between them, and exposure, push,
print exposure and format reach the shader as uniforms. That is what
lets a mask layer hold film settings of its own.
The section now says so, and that the film's Exposure on the whole
photograph is the one setting that rebakes, because the enlarger's
filtration is solved against it.