I think you will find the coaches here will roughly fall in two different camps:
- First, the hardworking ones who like Ben suggest you learn a ton a various frameworks and hope you have the right now available in your backpocket / back of your head
- Second, the lazier ones like myself (I'd call ourselves 'pragmatic'), who suggest starting from a couple of tried-and-true frameworks that work in 95-99% of the cases: broadly, the business framework and the profitability framework
Where we meet again is that everyone will agree you still need to update to fit the actual case. In other words, everyone agrees you can't learn every single framework, and you will still need to adjust and think.
Look, here's what I strongly suggest: Learn the business and profitability frameworks really well, so you always have available in a bind. Everyone agrees you need to learn these ones. Then, go back and practice cases with coaches and fellow candidates as you normally would. If you feels like it, keep learning about additional frameworks on the side. No matter whether you are on the more pragmatic camp or not, you will still have to adjust the framework in nearly every instance. This is where being MECE and following the 80/20 rule will serve you well.
At the end of the day, you will need to practice a lot regardless - there are no shortcuts.
Hope this helps, good luck in your prep