So Garmin has yet to address this issue customers are requesting for the last FIVE years, so maybe you all at Training Peaks can help and address from your end.

Need a way to disable workout notifications on GArmin watches based on workout builder syncs. Specifically, we don't want alerts of thresholds below or above the range showing up. Only want alerts for the transition to the next phase of workout. When we do short intervals the transition alerts get lost in the threshold alerts.