My answer in the same thread is still valid
Without permission from the streamer to read bits events, which is needed for PubSub/EventSub as it’s scoped, you’d have to connect to the chat for each streamer playing the game and capture the bits usage from chat itself. Then disconnect from that chat if/when they change games/go offline. (Use get streams filtered by game_id to get those live with the game in question)
However you won’t know if a bits usage event is due to the game being played or the bits user jsut wanting to support the streamer regardless of the game. Which is why it’s not included in the game analytics since it’s not directly game related. (So probably not statistically significant really)