Question for Calibre fans, what do you use to convert your ebooks to audio books or just general TTS? And, since managing your own (usualy de-DRMed) files is i

Question for Calibre fans, what do you use to convert your ebooks to audio books or just general TTS? And, since managing your own (usualy de-DRMed) files is important to you, do you also feel like you want offline audio files? I'm asking because I'm working on an app for myself that converts my Calibre and Zotero books to clean mp3s for listening on my own. I also find that offline conversion results in much better quality TTS outputs instead of apps like ElevenReader or Speechify.