Would love to see a causal model [0] to help better understand all of the mediators considered as well as confounders. I'm close to finishing up an interesting read from Judea Pearl/Dana Mackenzie - The Book of Why: The New Science of Cause and Effect [1]. Talks alot about Causal Models, Causal Inference, the 3 ladders of causation, etc. I liked the graphical approach to help outline exactly how one thinks about direct and indirect effects and how it facilitates counterfactual analysis and causal mediation analysis.

[0] https://en.wikipedia.org/wiki/Causal_model

[1] https://en.wikipedia.org/wiki/The_Book_of_Why

McElreath's Statistical Rethinking is also a great reference for causal thinking and modeling.