Matt Colville's YouTube channel has a ton of this kind of content, especially during his "Running the Game" videos where he did a lot of the prototyping for MCDM stuff as well as how to make narrative ideas fit into a system based on the intent of the system.
He talks a lot about d&d 4e which serves well for this type of content since it was such a different system than other d&d/d20 in general, and also very much the opposite of fate/apocalpyse world/other narrative-focused systems.