Hi! What you are asking is whether there is a difference in approach between new product launch or new market entry. Well - the fundamental decision logic remains the same of course! And let me tell you a secret: the principle logic is identical across basically any kind of decision option that a client wants the consultant to assess!
A market entry/product launch/company purchase/capacity expansion/company acquisition/ etc. etc. makes sense if (i) it is economically viable, (ii) the client has/can acquire the required capabilities, and (iii) the risks are manageable. Economic viability is the central analysis to conduct and should be centered around value creation. You disaggregate value into its quantitative components and sub-components with a rigorous logic tree, and then you map qualitative drivers to each quantitative sub-component.
THIS is how you approach cases in a rigorous and bullet-proof way! Structuring a case means you outline the logic according to which you will answer the precise question of the client. Structuring does NOT mean to provide a structured list of the areas ("buckets") that you want to look into! Once you understand this, and once you have learned how to properly build your case solving roadmap aroung this insight, you don't need all these nonsense frameworks anymore which are floating around these days. NONE of them.