Reasons to add sync flags to Bitcoin

This would have several benefits including improving mining decentralization, reducing variance in mining profitability, reducing or eliminating SPV mined blocks and empty blocks, making transaction stuffing by miners either obvious or costly, giving miners something to do while they wait for attractive transactions to appear, and allowing for more efficient price discovery mechanism for transactions. The sync flag could be easily implemented with a soft fork and would require a message consisting of the hash of the previous block, a Bitcoin address, and a nonce to propagate through the network at maximum speed. A proof of work that is targeted for 2 minutes would fund this system, and the protocol would be modified to demand that the block produced 10 blocks after the sync flag must allocate 25% of the block reward to the address published by the sync flag. Implementing sync flags would help alleviate centralization pressure due to latency issues and reduce the number of empty blocks.