Why not just exclude DAO packs from participating. I'd rather the DAO hold current packs than burn them. Burning helps current pack holders bags but hurts the DAO bottom line. No-one knows what the future holds but hopefully its 10X+ the player base. It would be wise to keep the packs to sell for future profits. Thus providing liquidity for the DAO to use in was thats to be voted on by SPS holders. If future markets doesn't allow for pack resale than the DAO can continue to hold until the market does. Its better to have extra options (holding packs) than to not have them (burning packs).
Edit:
I always thought it be a wise move to hold XX thousands of each set to introduce X years down the road as Retro Packs. Little cost would be required to do such (just holding) the DAO would have already paid to have the packs created. The DAO could commission the SPL company to re-introduce them.