One or two monospaced font options
I personally like monospaced fonts for reading. For me those are better for my one eye which has some problems with closely spaced proportional fonts.
I don't know if this is much work, but it would be great if you could add 1 or 2 monospaced options for the article view.
Eg: "Inconsolata" and "Akkurat Mono" (thick lined fonts).