Alright, so I still haven't solved the mystery of what exactly was causing the font to display as
serif as the file's "default font" but I figured out a slight workaround: replace all instances of
serif in the stylesheets with
sans-serif, which is what I read in and what I was having to change the text to. Sometimes the solution is easier than one thinks
I plan on writing into AO3's tech support team to see if they'll consider removing mentions of a default font for their otherwise fantastic epub output template. Cheers
