Main constraint you’re not modeling is how increasing margin size increases total pages and thus cost.
That’s why I’m saying it probably won’t need that for the footers. There’s ~10mm between running footer and text block, if that’s reduced to ~8 or 9mm and those 1-2mm go below the footer instead, that’s still plenty of space to clearly separate the two, while greatly reducing the “falling off the page” feeling. (And the colored bars that mark chapters are fine, no need to touch those.)
That’s why I’m saying it probably won’t need that for the footers. There’s ~10mm between running footer and text block, if that’s reduced to ~8 or 9mm and those 1-2mm go below the footer instead, that’s still plenty of space to clearly separate the two, while greatly reducing the “falling off the page” feeling. (And the colored bars that mark chapters are fine, no need to touch those.)
I see, I misread, yup that makes sense.