I just posted to Delving Bitcoin addressing all concerns and objections i could get my hands on: https://delvingbitcoin.org/t/addressing-community-concerns-and-objections-regarding-my-recent-proposal-to-relax-bitcoin-cores-standardness-limits-on-op-return-outputs/1697. These are actual objections and concerns raised by community members, taken literally with little or no reformulation to address the precise statement.

On Thursday, April 17th, 2025 at 2:52 PM, Antoine Poinsot <darosior@protonmail.com> wrote:

Hi,

Standardness rules exist for 3 mains reasons: mitigate DoS vectors, provide upgrade hooks, or as a nudge to deter some usages.

Bitcoin Core will by default only relay and mine transactions with at most a single OP_RETURN output, with a scriptPubKey no larger than 83 bytes. This standardness rule falls into the third category: it aims to mildly deter data storage while still allowing a less harmful alternative than using non-provably-unspendable outputs.

Developers are now designing constructions that work around these limitations. An example is Clementine, the recently-announced Citrea bridge, which uses unspendable Taproot outputs to store data in its "WatchtowerChallenge" transaction due to the standardness restrictions on the size of OP_RETURNs[^0]. Meanwhile, we have witnessed in recent years that the nudge is ineffective to deter storing data onchain.

Since the restrictions on the usage of OP_RETURN outputs encourage harmful practices while being ineffective in deterring unwanted usage, i propose to drop them. I suggest to start by lifting the restriction on the size of the scriptPubKey for OP_RETURN outputs, as a first minimal step to stop encouraging harmful behaviour, and to then proceed to lift the restriction on the number of OP_RETURN outputs per transactions.

Antoine Poinsot

[^0]: See section 6.1 of their whitepaper here https://citrea.xyz/clementine_whitepaper.pdf