I can confirm the one to one exchange. I've never heard of a two to one exchange.
One additional thought...if you plan on mostly ordering an appetizer, or even two, for most nights of your stay - you may want to revisit paying for the DDP. You'd average about $30 worth of food per day (TS and CS included) if you did this.
Average Appetizer - $8.00
Average Drink - $2.00
Average Dessert - $6.00
Average Salad at CS - $7.00
Average Drink at CS - $2.39
Average Dessert at CS - $3.00