There is a discussion about the possible use of polling, with a suggested rate of 6 blocks. The conversation then turns to the issue of locked up capital in the channel between A and S while waiting for B to claim their payment. A solution is proposed where A and S can overwrite the payment and send multiple payments before going offline, provided A has sufficient inbound capacity in other channels. However, if the channel is forced on-chain, such as in the case of S being attacked and losing their keys, the UTXO should be claimable in both a secret-revelation path and a timeout path. This requires a PTLC. The concept of eltoo is introduced, which allows A to cancel the payment to B until B has claimed the payment from S. A can force the channel to settle on-chain even if S does not cooperate anymore and doesn't tell A about the new update + settlement transaction.