Dunno, I've never thought of establishing setting and "big picture" (to use Luke Crane's terminology) in this way before.
Fate has something a bit like this in it's setup phase, but I've never played Fate. Does it have anything useful to offer?
MHRP/Cortex+ Heroic allows the GM to set up to three Scene Distinctions for free in each action scene, and the rest have to be paid for from the Doom Pool. Maybe the GM gets three uses of Force for free, and then every further move allows the players to introduce some favourable element into the fiction also (eg the GM has trolls, but the PCs have a bolt hole among the fairy folk of the forest).
Not so familiar with Fate, myself. I've read bits of old editions. Marvel Heroic instead yes, the Doom Pool mechanic is cool, a tool mechanically regulated for the Gm to use, preventing abuse.
Good point. Starting from what you say about the three uses of Force allowed to the Gm, I now think these might be represented by the three "Rerolls" for the Gm-facing conflicts during Neg. Phase.
So the flow of play during negotiation phase would be like the following:
Gm simply puts forward resources/stuff/npc/monster/factions (from the setting the table is playing in) to establish a starting point in play.
Pcs spend their Background Slots to Negate the effects of what the Gm wants to establish.
This back and forth goes on until the Gm is cool with the last declaration from Players, or the Players stop it, declaring a conflict: Gm has to Roll. Everything already established before the roll is canon.
Gm rolls.
If successful, Player describes the outcome (the Player, in this way, has authority on describing how his/her Pc 'loses' the conflict, and also to add positive elements of canon fiction to mitigate the loss )
If fails, Gm describes how the Goal is more far than before, and, if feels so, Uses Force to reroll: describes what happens (eg: an Environmental Obstacle in the form of.......) and rolls again.
Repeat.
In the above example, the overall story arc Stake is "Town Under Siege by Orcs", the specific Goal of the rolled conflict is "The ranger is NOT warned by his orc sister while busy with trolls & bonfires"
Now Gm has spent one Use of Force (Env. Obs.) and the Ranger some BG Slots.
The negotiaton continues if there are other players, or the game zooms in to Scene framing in a new situation: Town is under siege.
Now: does another negotiation on Scene Fr. begins? If so, resources spent are refreshed?