Where would you place journalling RPG's like Thousand Year Vampire? How important really is causality to the experiential quality of exploration? What about setting details that are present acausally? It's horses in barding, say, rather than flying cars. I think one can play sim based on model alone (in the sense of model + rules = simulation) with freeform resolution. It's not that causality cannot support sim, only I think one can have the experience without causality (in system), too..
I don't have any clue as I have no exposure to the system. I'll leave that up to someone like
@hawkeyefan to give you some kind of informed answer if he feels so inclined.
I've always found it super-straightforward to see for gamist that system must matter, but for narrativist? No one has ever explained why in a way that accounts for all actual play. GM decides, and the experience is just the same as if we rolled biased dice (i.e. dice with modifiers or pooled). No one can really say why it matters that GM decides some things, except to say that they are passionately against it and it gets in the way of their personal expression. That's subjective.
I've talked about this many, many times.
Why does system (desperately) matter for Narrativist games?
1) Without "System's Say" (I'm sure you've heard me use this before) there can be no "play to find out what happens" which is a foundational tenet of Story Now games. Without principled (transparent and encoded), rules-directed, authority-distributed play, you've got one or more participants (or the whole collective) having a measure of authorial control and variability/constraint immunity over the trajectory of play that the quality of "play to find out what happens" which Story Now is built upon is compromised. It might be compromised for only one person like a GM who directs play even if subtly (by the myriad of ways they can put their thumb on the scales at any given moment of play...even if just through mediation of action resolution that is extremely vulnerable to bias/preconception/designs-upon-play because of little to no constraint placed upon them) or possibly more if play amounts to conch-passing storycraft...no conch-passing storycraft is not Story Now play...it doesn't remotely rise to the "play to find out what happens" threshold inherent to games with intricate and potent "system's say".
Again. NOW is the important word in Story Now play. That means THIS moment is what matters. If the expression of lack of constraint (operationalized by "system's say") lets me just resolve THIS consequential chunk of play how I see fit (unmediated), we've reached the failure state of Story Now.
Yes, single moments of play matter that much. Because NOW.
2) Story Now play was The Forge's answer (and system's before it, but Edwards et al worked to articulate it in an agenda for game design) to the Force-heavy era of the late 80s through the 90s. Principled (transparent and encoded), rules-directed, authority-distributed, binding "system's say" which is expressly hostile to Force was their answer.
And that answer works because (a) Force is kryptonite to "playing to find out what happens (NOW)" and (b) all of that "system's say" stuff yields exactly the type of rewarding moments of premise-addressing, thematically coherent play that they promise on the tin. Its not difficult to produce it if you just play the game the way its meant to be played. It IS difficult to play those games and deploy Force...which defeats the entire purpose of playing them in the first place...
...so why would you (not you...the hypothetical person who might be doing this described thing)?
3) Staying on premise and focusing play is (bare minimum) enhanced by coherent incentive structures. If that array of systemitized incentive structures and conflict/action resolution mechanics and consequences are coherently integrated, they absolutely help to align participant behavior and coordinate the conversation of play so it consistently propels play toward addressing the very questions that play is intended to address.