So around a month ago I requested to have $wgUseImageResize set to false for the Look Outside Wiki (https://lookoutside.miraheze.org/wiki/) because almost all the sprites are incredibly small and having them blurred didn't look great. The only problem that has occurred with turning this off is that I believe the Title Icon extension does not load title icons for any wiki page that would use them (for example, https://lookoutside.miraheze.org/wiki/Phillippe). The odd thing is that the search icons that would appear still work. I think this has something to do with the title icon trying to grab the "resized" image for wiki pages but because that doesn't exist anymore it doesn't load. I made a bug report a while ago but I don't know if it has been looked into (https://phabricator.wikimedia.org/T418699).
I don't know if this is the right place to ask about plugin issues, but I thought it would be smart to try at least.