Piper add-on configuration options per voice or at runtime

Feature Requests
1

I have been playing around with some custom voices and built-in voices in piper and have found that I would like to have different settings for the length scale and speaking cadence depending on the voice I’m using. Would it be possible to either have configuration options per voice in the add-on configuration (even if only possible in YAML) or be able to specify these specific parameters when calling the tts.speak action with piper as additional options?

Something like this:

action: tts.speak
target:
  entity_id: tts.piper
data:
  cache: true
  media_player_entity_id: media_player.study_speaker
  message: I enjoy the sight of humans on their knees... That was a joke.
  options:
    voice: edi
    length_scale: 1.5
    speaking_cadence: 0.5

This would allow the use of different settings for each voice simultaneously and make them all clearer and more natural-sounding, especially if you wish to use multiple voices at the same time.

2

I did an issue-report about missing options. My message was:

Which other options are available in an action-yml?
In the piper docker-compose-container I can configure a default like:

    PIPER_VOICE=de_DE-thorsten-medium #
    PIPER_LENGTH=1.0 #optional. Voice speaking rate, 1.0 is default with < 1.0 being faster and > 1.0 being slower.
    PIPER_NOISE=0.667 #optional
    PIPER_NOISEW=0.333 # optional. Controls the variability of speaking cadence. Values above 1 produce extreme stutters and pauses.
    PIPER_SPEAKER=0 #optional. Controls the variability of the voice by adding noise. Values above 1 will start to degrade audio.
    PIPER_PROCS=1 #optional. Number of Piper processes to run simultaneously.

The only one I could figure out is working in the homeassistant-yml is the option "voice" (see above).
I would expect to find all options in the homeassistant-docs somewhere.

But was closed “as not planed”.