I think EV is one valuable (but incomplete) metric for evaluating charities. WFMs can capture EV as well as other variables that are harder to incorporate quantitatively. However, creating BOTECs to estimate EV is a lot faster than making a full WFM. Which one to use is, in my view, a question of whether the importance of your decision justifies that extra effort or whether your time would be better spent on other decisions/work.

Regardless which one you choose, you should be careful not to rely on just the one tool. EV reasoning is vulnerable to Pascal's Mugging and the Optimizer's Curse. WFM is vulnerable to the issues I talked about in my post and more. The underlying point is that we need to supplement our tools with critical thinking to ensure we're not falling victim to their weaknesses.

I'm glad you found my post insightful! Regarding time, I would probably recommend going through the process with iterative depth. First, outline the points that seem most valuable to investigate based on your goals, uncertainty, and any upcoming moral decisions. Then, go through the process of the project repeatedly, starting with a very low level of depth and repeating with higher levels of depth as needed. Between each round, you could also re-prioritize based on changing uncertainties and decision relevance.

I don't actually think there is much object-level knowledge required to engage with this project. If anything, I imagine that developing object-level knowledge of EA topics would be more fulfilling after developing a more refined moral framework.