● Simplified fee bumping for LN: funds in a payment channel are protected in part by a multisig contract that requires both parties sign any state in which the channel can close. Although this provides trustless security, it has an unwanted side-effect related to transaction fees—the parties may be signing channel states weeks or months before the channel is actually closed, which means they have to guess what the transaction fees will be far in advance.

Rusty Russell has opened a PR to the BOLT repository and started a mailing list thread for feedback on a proposal to modify the construction and signing of some of the LN transactions in order to allow both BIP125 Replace-by-Fee (RBF) fee bumping and Child-Pays-For-Parent (CPFP) fee bumping. In a follow-up email, Matt Corallo indicated that the proposal is probably dependent on some changes being made to the methods and policies nodes use for relaying unconfirmed transactions.