Currently, retroactively adjusting thresholds for past dates is a bit tedious—it involves filtering a date range, selecting activities, and adjusting via “edit.”
I’ve seen an interesting workflow where you simply select a specific date, enter the threshold value (e.g., FTP), and all workouts after that date (but only up until the next manually entered value) are automatically assigned that threshold. This dramatically improves threshold history management, especially when dealing with large imports of old activity files spanning long periods.
As a bonus, a small optional omment field would be great along every value, allowing notes like “FTP set via CP test,” “Suggested by Garmin or Intervals after a fast group ride,” or “Suggested by Intervals as new eFTP” to track how and why each change was made.