Is it possible in Xcode to set up a scheme so that the "Run" action will use the Debug configuration when running on the simulator, and the Release configuration when running on the device? (Note when I say running on the device I mean phone plugged into computer, and "run" button pressed as part of debugging. I don't mean once users download it to their phone, that would be the "Archive" action).
I don't know of any way to do what you want in a single scheme. You would need two schemes to get your desired behavior: one for the simulator and one for the device.