I have finally done something I’ve wanted to add to the archive for a while. It is now possible to view an entire arc as a single document and save that all-in-one document as html or pdf for later reading! (The print-ready minimal styling will apply to the pdf since you’ll need to go through your browser’s Print function to save as pdf.)
At the top of each fandom or arc index page is now a link to view that set of stories all-in-one. You can, of course, view an entire fandom worth of fic in this way, though I don’t recommend that for the high-density fandoms like PoT or KHR or FMA! And if you want to use the all-in-one format just for reading online, there are also comment links at the bottom of each story.