I’m greatly enjoying this discussion of custom moves — it’s the next thing I’ll be writing about, so it’s been on my mind. I would say that the game (and probably Vincent and Meg too) is comfortable with the making up custom moves on the fly. I have a theory brewing that custom moves are the “rulings not rules” of Apocalypse World. Come across a situation for which either a move doesn’t fit or isn’t desirable, make up one that does! The extensive instruction in the book on how to create moves is there I think not only because they knew people would be making their own moves but because the game wants you to make them. Especially in the context of moves surrounding threats. The text actually commands you to make custom moves in the case of “disease threat[s] or . . . disease-like threat[s]” (119).

For the most part, the moves have got you covered (as you pointed out in your previous post, Paul Beakley, the game is playtested to an incredible extent), but it knows you will need to tweak and adjust things, and it gives you all the tools to make those rulings moves when complications arise.