Advocates of the change highlight its ability to significantly decrease the size of Merkle proofs by approximately 50% for a standard 200-byte transaction. This reduction is not only relevant in terms of efficiency but also enhances security by addressing vulnerabilities associated with fake inclusion proofs. As the network's hash rate escalates, the cost-effectiveness of generating false proofs compared to mining invalid blocks decreases, presenting a growing concern. Moreover, the utility of transaction inclusion proofs extends beyond lite clients, potentially benefiting applications such as sidechains or future enhancements that might enable direct Merkle proof verification within script interpreters.

Critics of the proposal argue against the alteration of consensus rules due to the incremental nature of the benefits when considering the broader context of blockchain operation. The reduction in proof size, while significant percentage-wise, translates to a minimal absolute byte decrease and diminishes in value as more transactions per block are queried. Additionally, the simplification introduced by eliminating one complex verification step for inclusion proof verifiers is offset by imposing a new requirement on all validating nodes. This shift introduces a consensus "seam," complicating consensus rules without providing a clear advantage, as highlighted by a discussion thread.

Rebuttals to these criticisms suggest that any costs associated with implementing this change could be mitigated by incorporating it into a comprehensive package of updates, thus spreading the implementation cost over multiple improvements. The introduction of a simple rule excluding 64-byte transactions from validity is argued to be a straightforward and low-cost measure for full nodes to enforce, despite initial appearances of complexity. Furthermore, it is posited that developers tasked with implementing full node protocols are likely to possess a deeper understanding of protocol nuances than application developers, suggesting that the proposed changes would not unduly burden the developer community.

In summary, the debate encompasses both the technical merits of reducing Merkle proof sizes and the broader implications of adjusting consensus rules. Proponents emphasize efficiency gains and security improvements, while opponents caution against the complexity and potential unintended consequences of such changes. The dialogue continues to evolve, with contributions from various stakeholders seeking to balance innovation with the integrity of the blockchain ecosystem.