Louise, you ask if this ability to eat one bit of chocolate or biscuit is a genuine change in mindset or compliance, and I suspect it’s the former. You’ve worked through desire, created a new expectation, and feelings of addictive desire follow from that. It’s an example of the technique at work. Some people can do that (without leaving the entire item in the shops), while others find it difficult.
As for your question about being imperfect enough – it looks like that’s been answered!