First, let me say that I am not an expert in web accessibility. Unfortunately I think most people who are web developers aren't.

If you're using a continuous integration service it is pretty easy to add in-browser site performance testing to your suite of tests.

Yes, yes, one click deployment is amazing. And yet so last year. So I say, hell no, we want one push deployment. The dream cheeky USB button is neat. Let's deploy sites with it.

Short version: if you are testing and have configuration in settings.php you probably want to override the DrupalWebTestCase::refreshVariables() method.