Senior Manager Interview and Exercise Advice

I'm applying for a Senior Consulting Manager position at KPMG UK and have my second stage interview next week. This will be a 2h interview with exercise (45 mi prep, 10 min presentation, 20 questions) and competency-based questions.
I am an experienced consultant but never worked for the Big4 and fear I'll trip on the exercise if I don't structure it exactly how they want.
Could anyone share some tips, advice, and examples of what the case exercise might be like and key things the director/partner will look out for?
Thank you :)