Sibling Eviction for v3 transactions

Understanding the nuances of package replacements in Bitcoin transactions can be quite complex, but the correspondence provides some clarity on this topic. The discussion involves the Replace-by-Fee (RBF) feature, which allows unconfirmed transactions to be replaced by another transaction paying a higher fee. It's highlighted that with only 1 parent 1 child (1p1c) package relay and RBF, certain package replacements are possible under specific conditions.

The first scenario presented is a situation where two transactions, A-B and A'-B', both start with zero satoshis per virtual byte (sat/vB) and B' offers a higher fee rate than B. This replacement is deemed workable within the v3 package replacement framework. The same goes for a direct swap where A remains constant, and B is replaced by B' with a higher fee rate. These examples are illustrated using mermaid flowchart syntax which helps visualize the transaction relationships.

However, there's a query about a case where A-B is attempted to be replaced by A-C where C offers a higher fee rate than B. The consensus is that sibling eviction should be enabled to allow such a replacement, as it represents the most intuitive behavior for users. With Package RBF, the entire package, including transactions in the mempool, should be considered when assessing potential replacements. By implication, if A-C has better fees, it should logically replace A-B, enhancing the fee market dynamics and user experience of the Bitcoin network.