There's been some adequate discussion here that CX *does* keep tabs on members travel habits, including those who pay more and don't.
I also notice that the girls seem to recognize certain passengers, including me (I was even told by one and I want to meet her again before I meet Kylie (joke) :-).
Anyway, I've never had a bad experience in J or Y on CX (with luck, F will be my first time next year). I know the FAs are always busy with full flights and I just keep smiling. They never forget a smile.
I'm sure if you had a problem, CX *will* respond in a professional mannor. Don't worry about it, but remember Y is Y.
SHADO