I’d like to show the comments form on posts above/before the actual comments. I’m unable to find an option to make this change. Sorry if this has been documented somewhere.
Unfortunately, you’ll have to edit the PHP file as it dictates the sequence of the markup.
While it’d be nice to be able to simply filter things, you’ll most likely end up rewriting the markup within the snippets you hook things into when you rearrange things so you might as well edit comments.php.