On my wishlist would be a local model that can generate new voices based on descriptions such as "rough detective-like hard boiled man" or "old fatherly grampa"
You might be interested in this cool app that Microsoft made that I don't think I've seen anyone talk about anywhere called Speech Studio. https://speech.microsoft.com/
I don't recall their voices being the most descriptive but they had a lot. They also let layout a bunch of text & have different voices speak each line just like a movie script.
