I would like to suggest that Garmin introduces a third setting for auto-lap:
1) Auto-lap ON
2) Auto-lap OFF
3) Auto-lap OFF during workout
I understand that one can make a custom running profile with auto-lap off that can be used during workouts or turn auto-lap on and off but in reality this becomes tedious as one can easily forget to switch the profile before you start a workout etc. On top of that you have to keep replicating data screens between two profiles ...