Mozilla TTS has not been updated in 4 years (at least). The quality of the sound generated is rather poor, or at least I was not able to generate human passable sound using that tool.

tts --text "If you like to use TTS to try a new idea and like to share your experiments with the community, we urge you to use the following guideline for a better collaboration. (If you have an idea for better collaboration, let us know)" \
  --model_name tts_models/en/ljspeech/neural_hmm \
  --vocoder_name vocoder_models/en/ek1/wavegrad \
  --out_path test.wav

OpenVoice, as you very well mentioned, needs to become more mature before it can be used for the purpose I have in mind, as it shares the same poor quality that Mozilla TTS does.

I am currently playing with F5 which even has online tutorials: https://www.youtube.com/watch?v=ASFoTNpkM8o

It seems quite decent. I was able to run it on my local setup as well, which is a big plus. The problem I now face if twofold:

• I need to find a voice database with male voices in English (have no idea where to find one)
• I need to then train F5 or whatever tool I use with that voice

As a final step, I will also then need to learn and manipulate said tool to read paragraphs, instead of 1 liners.

You might want to check out VITS or XTTS from Mozilla/TTS, which can run on CPUs and supports training with custom datasets. Another option is OpenVoice (if it matures further) or Voxygen (which has some offline options). For datasets, LibriTTS and Common Voice (filtered for quality) are good English sources. You can also try RHVoice—not the best quality, but flexible for CPU usage.

For community support, the TTS subreddit, GitHub discussions for Mozilla/TTS, and OpenAI TTS communities might be helpful!