Version 1.4 intended for Wear OS 2.0 and later (tested up to at least Wear OS 4.0). Relies on the latest APIs, which requires registering a lightweight notification listener service.

Should hopefully get a Play Store release on both the phone and watch stores. Until then, install the watch APK using ADB or something like Wear Installer. Then execute the ADB command listed in the readme file below when connected to the watch:
https://github.com/blunden/DoNotDisturbSync/blob/master/README.md