From mediawiki.org I assume nearly all the image that are being uploaded are MediaWiki screenshots. So during the licensing stuff, it would be nice if there was a checkbox asking if it was a MediaWiki screenshot, and automatically added {{MediaWiki screenshot}} on Commons. Presumably this would be configurable on-wiki somehow.
Using the in-editor uploader is sooooo much easier, but I still have to go to Commons to perform this last step :( (e.g. https://commons.wikimedia.org/w/index.php?title=File%3ASpecialChangeContentModel.png&type=revision&diff=189227401&oldid=189227292)