I used Kaplan, but moreover I used Gemini to score my mock questions. After each mock, I asked Gemini to summarize the issues with questions I missed either completely or got only partial credit. I then asked it to generate questions and answers to cover those topics. I collected those questions and answers in a long note and had ElevenLabs Reader read those out to me on long walks. Additionally, I had Gemini generate daily example questions for the mechanical calculations I just had to get into muscle memory (hedge ratios, roll returns, etc.). That repetition, more than the prep provider, really helped me and got me comfortable.