I made an interesting discovery today. I started my run with the route and map active, two CIQ data fields (DRNG and Stryd), no music, and everything went relatively well. Button presses were executed quickly, and the map scrolled smoothly while navigating. I was very surprised. I usually run with music, and this was the first time I had a regular watch that responded properly to buttons and displayed the navigation properly.
Halfway through the run, I activated the music (Spotify), and the problems began. The map was only half displayed, scrolling the map simply pushed the map out of the screen, and the watch couldn't keep up with the map display. Button presses took forever. Then I paused the music briefly, and the map refreshed faster again. After starting music again I wanted to select a different playlist in Spotify... the system crashed.
My theory: The CPU of the 970 is throttled so much to save power that running multiple additional tasks can lead to latency in certain apps and even a system crash.