Doppler v2.1 and later has a context menu item named Edit Info With>Yate. The selected files will be opened in Yate according to the current Open Mode settings. The first time this is done you will be asked if you want to enable the Settings - Audio - Common - Set Doppler refresh attribute setting. The setting will cause Yate to write an extended file attribute whenever it saves a file. This will allow Doppler to detect that files have been modified and that it should reload the updated metadata. Doppler removes the extended attribute when reloading the files. It is recommended that you enable the setting.
The functionality works best when audio files are located in Doppler's media folder. In Doppler's application settings you can switch the default folder of ~/Music/Doppler to the root folder of your collection.
Doppler renames and reorganises files when you copy them into your library. Turn off Copy Imported Files into the Doppler Media Folder in Doppler settings to reference the original file instead.
You can add Doppler to Yate's File>Open With menu. When you do a File>Open With>Doppler, the selected files will be added to Doppler's library.