Thanks for that detailed response Argun! For clarity - I was intending to test the "suspension" as you mention. In this state our web-sockets connection is lost, however we are unable to handle the disconnection event within our application code at that point in time because the application is not given the runtime, as you mention. Thus when the app is resumed we need to be able to detect that the web-socket connection was lost, so we can re-fetch missed data. Disconnecting Xcode & waiting reliably results in this suspension, so that's solved my needs (though a button to trigger this state would be very helpful!). Thanks very much for your help!

OK, it seems that detaching the app from Xcode & fully quitting Xcode helps to make the above steps more reliable (backgrounding the app and leaving it for a minute or so). It would be great if there's another way to achieve this, however, so I'm still interested if anybody knows any