Default for workout builder
It would be nice if the workout builder remembered what metric you used in the past. For example, whenever I create a swim workout, I have to select yards, not meters. It would be helpful if TP remembered that I last built my workout in yards.

March 14, 2018
The workout builder has been updated with a few a new features:
1. Workout steps can be set to have an open duration. For most devices pressing the lap button will take you to the next step of the workout. This is currently available for Garmin devices. We expect other device manufacturers to implement this feature shortly. A suggested duration is still required for these steps so the planned duration and TSS for the workout can be calculated. This value will also be used for devices and file formats that do not support this feature.
2. Target values for the step (power, pace, heart-rate) can now be set to a custom range. This range will be used for Garmin devices. Most indoor cycling platforms require a single value for ERG mode, and the midpoint of the range will be used in that instance.
3. Cadence can now be set as a second target for each step of the workout. Currently cadence is supported for bike workouts in Zwift. We expect other device manufacturers to implement this feature shortly.
4. The last settings used when creating a new workout are remembered, so you do not always need to choose the target type or other options.
Not every device or platform will support all of these features. Here is a short list of partners and which features each one supports at this time.
https://help.trainingpeaks.com/hc/en-us/articles/360001652912
The following FAQ pages have additional information on these new features.
https://help.trainingpeaks.com/hc/en-us/articles/235164967
https://help.trainingpeaks.com/hc/en-us/articles/115003385172