Or maybe I could keep it simple.... a Boon point equals a +1 to the next Saving Roll (within 12 hours) of the Same type (Snags equal -1). Additional Boon/Snag points result in either extended duration (+12 hours), or increased modifier (+/-1).
For example, the TN for a Save against a spells is 24 vs. Con. You make a Con Save, and get a whopping 52, 2 Boon Points, so you can get a +1 to Con Saves for 24 hours or a +2 to Con Saves for 12 Hours. -- and as always, it is the player's choice....