I've had Claude ignore crystal clear written instructions and try commands that I told it not to run.
That's LLMs 101! As the context window fills up, there are too many things competing for attention all at once, and eventually nothing works. When it starts going off the rails, /compact.
you missed the point; in a high risk situation like trading, you can't afford for Claude to "start going off the rails" in the first place
It's also not a problem that's limited to the context willing filling up.