Had early access to Gemini 3.8 Flash, it is a very good Flash model, but not equivalent to a frontier model, though. Here is Gemini 3.8 Flash's version of the shader with the same prompts (which it provided very quickly)
The drowned neo-gothic tower twigl shader created by Fable 5.1 with the same prompt. (compare to Fable 5 in the quoted tweet, and other models before that)