A pivotal change involves transitioning to a Pure Type-Length-Value (TLV) format for all new messages. This shift is motivated by the desire to enhance the efficiency and flexibility of information exchange during gossip syncs. By adopting the TLV format, previously used in Bolt 12 messages, the proposal aims to facilitate the inclusion of additional data such as Simplified Payment Verification (SPV) proofs without requiring this information to be covered by the announcement signature. This approach not only allows for the sharing of a broader range of information but also grants nodes the capability to disregard optional fields within the unsigned range if they deem them unnecessary or incomprehensible, thereby streamlining data handling processes.

Another significant aspect of the proposed updates includes adapting message structures to support more flexible announcements and updates for Pay-to-Witness-Script-Hash (P2WSH) channels. The introduction of Schnorr signatures for these channels proposes a method wherein channel peers would first exchange nonces through channel_ready messages before moving forward with announcement_sigs_2. This methodology aims to permit the announcement of channels, whether newly formed or pre-existing, at any stage of their lifecycle, contingent upon mutual agreement and understanding between peers, as indicated by feature bit 2. This adjustment seeks to simplify the transition of unannounced channels to announced ones, potentially improving network connectivity and overall functionality.

To implement these comprehensive protocol updates effectively, the proposal suggests a phased rollout, signified by the introduction of three new feature bits. These bits would indicate a node's capabilities concerning the comprehension and generation of new gossip messages, re-announcing P2WSH channels, and providing SPV proofs. Additionally, a potential fourth feature bit could denote a node's capacity to upgrade unannounced channels to announced status, thus promoting enhanced flexibility and adaptability across the network. Overall, these proposed changes aim to advance the protocol's efficiency, security, and usability, reflecting the community's concerted efforts to refine and evolve the system in alignment with technological progress and user requirements. For further details on the current proposal, you can review it directly on GitHub: https://github.com/lightning/bolts/pull/1059.