1240 new lines?
That's 12.9 tokens per line when given 16k output context, which seems borderline doable, I'll grant you that... but mind you that these agentic code assistents don't need a single pass to accomplish their acts of verbosity.
They can just plan, stew for minutes on end, derail themselves, stew some more, do more edits, eat up $5 in API calls and there you are. An entirely new 1000+ line file, believe it or not.