Yes, so I am happy when I see a game engine uses renpy https://www.renpy.org because this engine has a built-in TTS, some of the time the developers did not test their game with this feature but since it uses python the user can hijack the TTS and use regex to cleanup stuff and I also pipe the TTS through my own configured TTS. I see people re-implementing their own visual novel game using Unity, the result is an inferior experience in all possible ways(not only accessibility).

Latest RPG Maker can export the game as html/JS , I think people created plugins for TTS but I personally wrote my own hack code that I inject in the game and pip[e the text again into my own configuration.

There are other HTML based game engines for text based games, those are also good for accessibility because you can use your existing tools to speack the text or you can change the fonts if that helps.

For DirectX/OpenGl games I tried using OCR , this is slow and it also has big problems if the game uses "fantastic" fonts = fonts that look like handwriting or other iregular fonts.

Maybe when I will have more time I could learn how to inject code in Unity or Unreal games and attempt to detect when the code renders fonts and pipe the text out of the game.