Relax OP_RETURN standardness restrictions

The discussion revolves around the intricacies of implementing restrictions within Bitcoin's relay and mining protocols, specifically addressing the potential harm of making relay rules more restrictive. The conversation highlights a nuanced understanding that while historically, the community has resisted restrictions on already accepted transactions, there are justified exceptions. A notable example provided is the High-S signatures issue, where active attacks were mitigated by allowing third parties to convert high-S signatures to low-S, demonstrating that reductions in relay permissiveness can be both uncommon and exceptional.

Furthermore, the dialogue touches upon the importance of differentiating between relay and mining behaviors, suggesting that changes should first be deployed to mining behavior to avoid unintended consequences on the network. This approach acknowledges that while it might seem that relay and mining should operate under the same configurations, their separation is crucial for network health. The conversation also delves into specific scenarios, like the handling of "quadratic hashing bloat txn," to illustrate the necessity of removing harmful transactions from consensus validity rather than merely preventing them at the relay level.

Moreover, the exchange explores the concept of forward compatibility and the risks associated with allowing non-standard transactions, which could undermine this principle. It suggests a careful consideration of exceptions to standard policies, emphasizing that any deviation from the general principle should be accompanied by a strong rationale.

The discourse also critically examines Bitcoin Core's existing policies, distinguishing between consensus rules, which have the force even if some miners do not agree, and relay policies, which can become moot if ignored by miners. This distinction underscores the challenge of ensuring that policies remain effective in guiding miner behavior without becoming obsolete due to non-compliance.

Additionally, the conversation addresses the practical implications of policy decisions on node operation and the broader ecosystem. For instance, choices around data storage and block size growth directly impact the feasibility of running a full node, reflecting on the balance between enabling new functionalities and maintaining network accessibility and performance.

Overall, the discussion encapsulates a thoughtful examination of how Bitcoin's technical policies influence its operational integrity and future development. It underscores the complexity of enacting changes within a decentralized system, highlighting the need for careful deliberation, clear justification for exceptions, and a recognition of the broader implications of these decisions.