It highlights that due to the nature of Lightning's use of disclosed secrets to invalidate old state, it is not necessary to keep every signature from the counterparty indefinitely.

The email mentions that for each channel, there is a requirement of having a minimum incremental relay fee of 1sat/vByte by default. This information is relevant in the context of discussing the need for combining multiple SIGHASH_SINGLE transactions together. The email explains that the savings obtained from combining these transactions are not significant, as the reduction in size is only around 18 bytes for certain fields such as nVersion, nLockTime, txin, and txout size.

Furthermore, the email mentions that the HTLC-timeout transaction occupies around 166.5 vBytes, resulting in a savings of just 11% when combined with other transactions. However, if there is a need to fee bump and add an additional input, the space occupied by the input and the need for a change output might make a pre-signed transaction a better option.

It is important to note that the email assumes the presence of numerous HTLCs in flight that need to be spent, although this may not always be the case. In conclusion, the email provides insights into the optimization possibilities and considerations when dealing with ephemeral data storage and transaction efficiency in the context of HTLC and commitment transactions within the Lightning Network.

For more details, you can refer to the original email at: [https://petertodd.org 'peter'[:-1]@petertodd.org].