The Benchmark Exercises is a nice feature. Unfortunately, manual update makes it useless.
Does Garmin actually pay attention to these forums for feature requests? A while ago I submitted a feature request through the Garmin support line. Unfortunately, it still isn't implemented.
Garmin Connect knows the exercise, number of reps, and weight.
Please make so the Benchmark Exercises are updated automatically with the data from a Strength Training session. Otherwise, requiring manual input makes Benchmark Exercises practically useless.