Greasy Fork

Great script, has been very helpful for years.
But recent updates seem to change all icons to iconfonts.
This breaks on Firefox with "Allow pages to choose their own fonts, instead of your selections above" disabled.
Firefox with "Allow pages to choose their own fonts, instead of your selections above" disabled is a must for me to browse Japanese sites on Windows without hurting my eyes for years, since default Japanese fonts on Windows are so terrible.
If you don't mind, I would like an option to have either svg icons or iconfonts, and let me opt in svg icons.

That would make it really hard to handle icons. I think you'll start running into this a lot, since icon fonts are becoming more and more common. That option would make more sense if it was per-language, so you could override just the languages you want, and icons could be set to a separate language. It looks like somebody reported this problem to Firefox, but it's been basically ignored: https://bugzilla.mozilla.org/show_bug.cgi?id=1638585

You could try using Stylish to override fonts (https://addons.mozilla.org/en-US/firefox/addon/stylish/), with a stylesheet like:

:lang(ja) { font-family: sans-serif !important; }
:lang(en) { font-family: serif !important; }

If I set the icons to have a language of "icon", they won't be affected by this. I'm not sure if that's similar enough to what Firefox's option is doing, but might be worth a try.

I added the lang tags to icons in r141 in case you'd like to try that.