Bitcoin Core 30.0

Bitcoin Core v30.0 now relays/mines txs with multiple OP_RETURN outputs and raises the default -datacarriersize to 100,000 bytes. This is a mempool policy change, not consensus. The move has already gotten negative feedback from devs worried it invites more arbitrary “junk” data on-chain. Bitcoin Core’s stance is harm-reduction: OP_RETURN is prunable and cleaner than UTXO-stuffing workarounds that people have been using anyway. Economically, more fee-paying bytes means miners are unlikely to reject it.