You are just talking about L1 scripting. In LN we don't even have multisig. TARO is not a safe way to put dollars on the LN, they are a way to put IOUs, which carry a counterparty risk. Even your precious regulated instrument carries counterparty risk. Unlike a dollar denominated token that can be redeemed trustlessly in a smart contract at any time for it's equivalent value in BTC. Math > regulation, welcome to bitcoin.