5. Why the sound will cut out occasionally when using the Q1MkII with iOS devices?
For the older versions of iOS 10/11, when running in multi-task, it would degrade the priority of USB AUDIO, which allows some other APPs to take over the audio output channel if they access microphone, camera or push notifications in the background. As a result, the audio output of the music player app will be interrupted for a very short time and soon resume.
However, Apple has fixed this issue in the iOS 11.3. So it's suggested that you upgrade the iOS to the latest version.
Or if you want to stick with the old iOS, you may try setting your iOS device to airplane mode when listening to music, which can help solve the issue for most devices.