I agree... I think you should choose your battles. Like I was trying to say before, figure out what the top priority is (getting out of proving mastery 3X, or focus on challenge level overall.) If you can focus on challenge level overall, then perhaps the issue with the 3X rule will disappear. My take, with my child was, regardless where we were at, the rule was the rule and didn't go away so we focused our energy on the overall challenge level vs. that small part.

GOOD LUCK!