My first attempt. Feedback and feature requests are more than welcome !!!!!!
https://apps.garmin.com/en-US/apps/741713ae-818a-4c83-b53a-9df273209ca6 has link to both the watch app and the companion android app (https://play.google.com/store/apps/details?id=seshu.com.vivotasker).
Install the watch app first and then the android app, launch the android app, pick your favorite contact and use settings to customize your pre-canned text responses and your watch app should now pick it from there !!!!!!