What about a field to increase the speed of TTS systems? Most of them allow to modify that with parameters, why not in the frontend?
NanoTTS is good, but too slow, (if you know how to do that in the docker-compose in the rhasspy configuration please share it)
nanotts has a speed flag, which you can set in your profile.json
Definition of flag: https://github.com/gmn/nanotts
How to set the flag in profiles.json: https://rhasspy.readthedocs.io/en/latest/text-to-speech/ in section eSpeak (yes, eSpeak, no typo).
It doesn’t work for me, so either the “arguments” property is not read in json for nanotts or my setup is broken. Maybe it works for you?