从说明上看 

Fable 5 is back. 
▎Until July 7, you can use up to 50% of your plan’s weekly usage limit on Fable 5. If you hit your limit, you can continue on Fable 5 with usage credits. Fable 5 draws down usage faster than Opus 4.8. 

感觉是 “如上” 用不了多少就会限额。 
测试了一下糖果问题 
❯ /model
  ⎿  Set model to Fable 5 and saved as your default for new sessions

❯ /model
  ⎿  Kept model as Fable 5

❯ 不使用任何外部工具回答以下问题：

  在...