Amazing, I will study that. Why was the solution from Liana prefered in the end?
We worked on a vault system managing watchtowers and cosigning servers before Liana: https://github.com/revault
The presigned timelock tx was called a unvault tx and the watchtowers were able to cancel (send funds back to the vault) during the time of the locktime according to specific spend policies.
Discussion
We had poor demand for it (complexity of self hosting services for users) and we had a chicken and egg problem with hardware wallets manufacturers who did not want to implement miniscript without users asking for it. Also presigned txs are a pain in case of mempool fluctuation and most of the core improvements (package relay etc) were missing.
So we sat on a beach, asking ourself what the simplest wallet we could create that illustrate the power of miniscript and we came up with Liana.
Antoine did the work to integrate miniscript in bitcoin core and I worked with Stephan and Salvatore to have compatibility and tests with specter-diy and Ledger.