Optimism pushes network speeds to 200 ms, but standard data feeds are dropping key information

Optimism is targeting 200 ms subblocks on OP Mainnet, cutting the preconfirmation interval from 250 milliseconds in a rolling change targeted for Aug. 31. Subblocks, formerly called Flashblocks, are incremental updates the sequencer sends while it is still building a normal block, giving apps feedback before that block is sealed.The 20% speedup carries a quiet compatibility risk. Optimism's migration notice says four fields will remain in each streamed payload but stop carrying usable data: state_root, block_hash and withdrawals_root will be all-zero values, while withdrawals will be an empty list.The payload type remains ExecutionPayloadFlashblockDeltaV1, so software can continue parsing the stream without raising an error. Fields including receipts_root and logs_bloom will still contain real values. That combination makes the migration easy to miss in systems that treat successful decoding as proof that every field is meaningful.Why 200 ms subblocks make the provider boundary matterSubblocks are preconfirmations, not finalized blocks or state commitments. Optimism's technical explainer says direct stream consumers should treat the zeroed state root and block hash as absent and de...