You have your route uploaded, and the algo knows what work you need to do, so can it develop a workout based on those? The same sort of tech that Strava Live Segments would use.
Would take the faff out of the outdoors workouts (which are amazing by the way, made structured training fun for me again), where you’re trying to make the geography fit the workout.
Pretty sure TrainerRoad can pull this off, or will be the first to pull it off.