I am using the TRAINER_EFFECT in perfs.xml actively to have full control over the difficulty setting in race and training situations. I wouldn’t have to do that if I could see the exact value in the GUI.
Sometimes I find that I have set a wrong value. I am either spinning out in the race finish and can’t put out the required watts, or I’m having a too low cadence up hills.
It would be nice to be able to adjust the difficulty setting on the mobile app. The same way you can adjust the resistance during a workout.