speech-dispatcher
If you are referring to locally generated speech synthesis, the respecting outcome as far as I am concerned generally sounds generally poorer, and is more difficult to manage. However you can check out the original project https://gitlab.com/christosangel/sapo, where the audio files are generated locally.
Indeed piper performs very well. Thank you for the input, I will most certainly consider adding the option to select tts engine in the near future, piper sounds totally worth it.