I do the same, but delegate to codex instead via the /smux skill. It's expensive, but I get one long-running Claude context window and one frequently compacting codex, and this saves me from needing to re-gather context all the time.
Per the OP's technique, I'll use Fable for intensive planning moments, then switch back to opus when things are going well.
Per the OP's technique, I'll use Fable for intensive planning moments, then switch back to opus when things are going well.