Cases can be more "unstructured" or "umpredictable", but the way to prep is the same.
What gets trickier, longer and more important is FIT. Some interviews, even 2/3 is FIT.
If you want to deepen your knoledge, the "Integrated FIT guide for MBB" has been recently published in PrepLounge´s shop (https://www.preplounge.com/en/shop/tests-2/integrated-fit-guide-for-mbb-34)
It provides an end-to-end preparation for all three MBB interviews, tackling each firms particularities and combining key concepts review and a hands-on methodology. Following the book, the candidate will prepare his/her stories by practicing with over 50 real questions and leveraging special frameworks and worksheets that guide step-by-step, developed by the author and her experience as a Master in Management professor and coach. Finally, as further guidance, the guide encompasses over 20 examples from real candidates.
Furthermore, you can find 2 free cases in the PrepL case regarding FIT preparation:
Intro and CV questions > https://www.preplounge.com/en/management-consulting-cases/fit-interview/intermediate/introduction-and-cv-questions-fit-interview-preparation-200
Motivational questions > https://www.preplounge.com/en/management-consulting-cases/fit-interview/intermediate/motivational-questions-fit-interview-preparation-201
Behavioural questions (ENTREPRENEURIAL DRIVE) >https://www.preplounge.com/en/management-consulting-cases/fit-interview/intermediate/behavioral-questions-entrepreneurial-drive-fit-interview-preparation-211
Feel free to PM me for disccount codes for the Integrated FIT Guide, since we still have some left from the launch!