It feels to me that a some refactoring is needed around servers and mappings...
But now I am thinking a some refactoring is needed between Deployment Server Configurations and PHP/Servers. My first though is that there should be a top-level item called just Servers, and that servers have deployment, debugging, and other aspects (perhaps in tabs). That seems more natural. Like with Deployment, you can choose a default Server and it will be the default for Preview, Run, Debug, and Deployment unless you override it in their specific configurations.