The first major update involves transitioning all new message structures to a Pure Type-Length-Value (TLV) format, removing the fixed field for signatures and instead incorporating everything within TLV fields. This change, inspired by Bolt 12 messages, aims to enhance information exchange during gossip sync by allowing additional data, like Simplified Payment Verification (SPV) proofs, to be requested and included without being covered by the announcement signature. Not only does this allow for greater flexibility in what information can be shared, but it also means that nodes have the option to discard optional fields in the unsigned range if they're not needed or understood, improving efficiency and customization of data handling.

Another significant proposal is the adaptation of messages to facilitate Pay-to-Witness-Script-Hash (P2WSH) channel announcements and updates more flexibly. This would involve using Schnorr signatures for these types of channels, requiring a process where channel peers exchange nonces through channel_ready messages before proceeding with announcement_sigs_2. This method introduces a way for channels, whether new or existing, to be announced at any point in their lifecycle, provided both peers agree and understand the process, as indicated by feature bit 2. The suggestion aims to simplify the upgrade of unannounced channels to announced ones, potentially enhancing network connectivity and functionality.

To address the challenges of transaction verification in channel announcements, the inclusion of an outpoint for the funding transaction is proposed. This approach benefits nodes with txindex enabled, allowing for quicker transaction fetching. Moreover, the option to include SPV proofs in channel announcements caters to light-client nodes, facilitating easier transaction verification without necessitating a full chain backend. These modifications are designed to streamline the verification process across different node types, ensuring more efficient and scalable network operations.

The implementation of these updates is suggested to be rolled out in phases, signaled by three new feature bits indicating a node's capabilities regarding the understanding and creation of new gossip messages, re-announcing P2WSH channels, and providing SPV proofs. A potential fourth feature bit could further indicate a node's ability to upgrade unannounced channels to announced status, fostering greater flexibility and adaptability within the network.

This comprehensive overhaul aims to enhance the protocol's efficiency, security, and usability, reflecting the community's collaborative efforts to refine and evolve the system in response to technological advancements and user needs.