Great suggestions! This forum is for users and I don't believe it's monitored by Garmin for suggestions. I do believe you can email support to suggest a feature. That said, Runner's World has a training pace calculator that uses the same language. I plugged in my "goal time" for the 10k I am shooting for and use that to determine what my "easy run" pace should be.
https://www.runnersworld.com/uk/training/a761676/rws-training-pace-calculator/