Graftroot: Private and efficient surrogate scripts under the taproot assumption

The email thread discusses introducing functionality to make a script invalid after a certain time, which can improve the utility of a construction despite its previous bad re-org behavior. The proposed timelocks would be valid before a certain time or block height, and invalid after, in contrast to current timelocks. This would allow for exclusion of old delegates based on timing/block height arguments or pre-signing delegates for different periods of time. Another topic discussed is the unilateral key rotation without invalidating the interests of other parties in the existing multisig, at the cost of storing the signed delegation. However, the word "rotation" may not be entirely accurate as the original setup remains able to sign. The old key could still sign alongside a new key if all parties agree.