From your question, I believe you still need to understand how to think about strategic business issues. VC cases (or PE cases, or any other investment scenarios) are completely identical to all other strategic issues, and hence I believe it is completely senseless to ask for specific "frameworks" (the same is true for "market entry frameworks", "product launch frameworks" and all the other nonsense stuff that is floating around). As an MBB consultant, you also would not use a "framework" in real life! You just need to understand the core of the problem.
If the question is whether a VC fund should invest in a target, then, in essence, you need to check whether the return on your investment exceeds the minimum ROI required by the client (the fund). This return depends on how the fund actually intends to makes money - does it extract operational profits, does it intend to exit after a certain time frame, or both?
So you need to check whether the money inflow created in the future will be enough to justify the investment that has to be made today (most probably via the future resell price, since this is how VC firms usually make money). The resell price depends on the future valuation of the target, and this valuation in turn depends on a certain base metric (most probably "expected profit generation"). So this is what you need to analyze and quantify in the case. This is best done via a rigorous driver logic, visualized by means of a driver tree.
The interesting thing is that this principle thinking frame is not only true for VC or PE or M&A situations, but for 90% of all strategic decision cases that you will ever encounter (market entry, new product, capacity expansion, licence purchase, etc. etc.). It is always about value creation! If you learn to rigorously start your thinking from the principles of value creation, the typical case frameworks from well-known books like Case in Point etc. become practically obsolete, while at the same time your thinking becomes way more rigorous and mature.
Then for the structuring, there are a couple of simple notions that you need to adhere to in order to effectively set up and navigate strategic cases (for example, contrary to what is taught in the popular books, NEVER start with qualitative questions like "first I would like to understand the market context..." - this is exactly how you should NOT work as a consultan! This would be the definition of "boiling the ocean" ;-))