Yes
I have flipped my approach from planning with Opus 4.8 high and implementation with GPT 5.5 to planning with 5.6 high and implementation with Fable medium
lubujackson on Hacker News
In the thread “GPT-5.6 Sol Ultra produces proof of the Cycle Double Cover Conjecture [pdf]”, replying to this comment
Helped: Abstract thinking and concise output for high-level planning.
… In general, I would not be surprised if 5.6 was a much better tool for high mathematics than Fable based on the abstract thinking. For my dev workflow, I have flipped my approach from planning with Opus 4.8 high and implementation with GPT 5.5 to planning with 5.6 high and implementation with Fable medium (and I might even drop to Fable low). This is only on the company dime, of course.