Configuration file or env variable to define default simulator / AVD

The default simulator is the last one returned by xcrun. This can lead to an undesirable default, especially if simulators for multiple versions of iOS are installed, or having to specify the desired default every time or create brittle run scripts. I'm not aware of any way through Xcode to manipulate the order or to "hide" simulators from the list without deleting them.

So I'm suggesting a way to locally set a desired default in the environment - perhaps in a configuration file, and / or environment variables. The benefit of a configuration file is that we could check it in to ensure developers adopt the targeted OS versions.