en_US/Ryan can't pronounce 9/11 as "nine eleven"
I think there's a pretty good case that the majority of times 9/11 will be used in US writing, it means "nine eleven" and not nine elevenths or 9 divided by 11 or nine slash eleven, etc.
So I don't really know if this is the right way to go about this, but Ryan also can't pronounce "neoconservative" (or possibly "neo-conservative") and ninteenhundred and seventy-one for 1971 is wrong from any point of view. Theoretically, AI should [eventually] be able to understand from context what is a year and what is a number, no?
World War I and World War II should be pronounced "World War One and World War Two" not "World War eye and World War eye eye". I assume WWII should be pronounced "World War Two".
This is a voice model, not a text normalization system (TN). It can only talk what you feed it. If you want to make "WW II" => "world war 2", you need to tell it so.