I’ve been modified the Injector extension to apply custom style sheets to IFRAME nodes as well, and because the site will delete and recreate this iframe multiple times as you do certain things, it will update the iframes in a repetitive manner to make sure the styles are there. I can actually share this modded version this would make it very easy to use this style sheet as well, however Chrome and it’s famous limitations all around will makes it kind of hard to install, since the missing policies. I would have to instead just submit this mod to the chrome web store to have a fine copy. But that’s would be a whole another topic with the original author, even tho he have been abandoned this project for some time.
Maybe other extensions have similar functionality so you can use them instead, and it would make the comment box work properly on Chrome as well.
Other than this limitation, everything else seems to be working just fine, and while f.lux can ease on the eyes it will won’t adjust you the layout which the style sheet does too as well. 
We should make this the official one as it is almost done already. Sooner the better.