IIRC, Brave Browser incorporates:
PDFium
SKIA Graphics Engine
V8 (JavaScript engine)
And the adjustment - Page Setup - settings necessary for the fix you hope to find, is somewhere in those components. Most likely, beginning with, how PDFium functions.
Not to discourage, but you may be facing a campaign to establish a Page Setup setting that would be somewhere following the “Headers and footers” switch.
You might edit the category-tags of your Original Post, above, to include a “feature request”.