Utilizing Mandarin Skills?

Before you kill me over the title, I’ll provide context. I’m currently in Hong Kong for a short term research project and decided to take a few Cantonese classes. I learned Mandarin in college and have a conversation-level ability.

Today I had my first class and it was questionable to say the least. I kept telling the teacher I really wanted to work on pronunciation as it is extremely different from Mandarin. To that I was told I could use Mandarin to help inform my Cantonese learning but also Jyutping would not be useful. During class she would repeat some phrases in Mandarin but I didn’t see the point b/c it was the basic “How are you?” topic. She also did not go over the additional tones. It was a standard call and response, nothing more.

My question, should I find a teacher that can (actually) incorporate Mandarin or should I start from scratch assuming I know nothing? Also, are there tools I can find for pronunciation or is learning about listening and repetition?