> all the flows where a model has the initiative are strictly biased towards unwarranted stops

Can you elaborate on what you think causes such a bias? My experience is that Qwen3.6, Claude Sonnet 4.6 and Opus 4.6/4.7 will work as far as they can given direction and a way to test their work. My so-far limited experience with Opus 4.8 is that it does stop somewhat earlier for feedback, but in places where I am glad it is checking assumptions or where I agree with it identifying a change in scope (for example, where the following work deserves a separate commit or merge request). I would call those justified stops rather than unwarranted.

Ask Claude! It will quote its constitution aka soulfile. It says the constitution instructs it to perform regular checkpointing no matter what.