Miners should set this option to a 1024 block payout.
The IPO/Premined coins have a value already of what investors paid for them. It is important to make this premined percentage as small as possible. This is possible by setting this value to 1024. This will make more money for miners as the investors will have to hold their coins for years if they want to get their investment back.
Why would a miner want to devalue his/her freshly minted coins?!? 
And meanwhile investors will push the price up.