It would be really helpful if one had the option to start with a workout and modify it rather than creating a workout from a blank slate. There are a number of workouts that I like, but would prefer to tweak (make them longer, reduce cool-down, increase wattage for certain segments, …). It is much more cumbersome than necessary to recreate them from scratch.
You can do that (on iOS and PC at least:
Hit that button, edit whatever you need, it’ll save in your custom workouts as a copy of the original workout.
Awesome. I never noticed the little icon there.
(And-just by chance-you highlighted probably my favorite workout.)