The proposal suggests simplifying the way addresses are identified by using keys based on the address type, such as 'ta' or 'tp' for taproot addresses, 'sp' for silent payments, and 'b12' for BOLT12, among others. This approach would enable wallets to more efficiently determine the appropriate action for different address types and understand the nature of the transactions they are processing. Additionally, this method offers a streamlined solution for integrating new address types that may not explicitly identify themselves through a bech32 human-readable part (HRP), aiming to reduce the size of QR codes.

A significant aspect of this proposal is the introduction of a generic 'addr' key for BIP21, designated for use exclusively with self-identifying address types, including legacy, p2sh, segwit, taproot, and any future addresses featuring an HRP. This initiative aims to ensure backward compatibility with existing address types while facilitating the incorporation of new ones without necessitating the creation of additional Bitcoin Improvement Proposals (BIPs) for each new address format. However, it acknowledges the necessity for new payment protocols like 'b12' to establish their own extension keys.

The suggested modification implies that wallets and sending clients would need to verify each 'addr' option against available address types, a process deemed manageable due to the functional equivalence of checking an HRP to verifying an extension key. This proposal represents a strategic move towards simplifying transaction processing and enhancing compatibility across different cryptocurrency address types, potentially leading to a more streamlined and user-friendly payment experience.