I'm flying in PAL in NZ on 1.3 with an iPhone 6s & GoPro 4 Black.. As long as you don't touch the GoPro settings via the app, the GoPro stays in PAL. Been flying in 2.7k 50p with no issue with the latest iOS app & solo firmware.
Same issue as Mario. I received solo this week, updated the copter / controller via the iOS app to 1.2 & then installed the Gimbal. GoPro firmware for the Hero 4 Black updated to the latest 3.0. Have never had a video feed from the gimbal once after a few hours tinkering and following the faq...