Thanks for the thoughts.
I'm training with heart rate and I intend to ride with heart rate because I'm notoriously bad at pacing myself. Training with the Leyzene, I've found it really helpful to get a consistent effort. It bleeps at me if I'm pushing too hard and move out of my intended zones. I just really struggle when I ride on feeling.

If you're using your phone, do you mount it to the bars and have it exposed, or do you keep stopping and getting it out of your pocket to check?