The context of lightning channel creation is not helpful since ECDSA signatures are inherently malleable. However, the deployable lightning model used single-sided funding to overcome this issue. To reliably spend from unconfirmed transactions, Segregated witness can be used but it requires a large hard-fork change. The proposal is to soft-fork it in. Another solution proposed by the author is sighash_noinput which can accomplish spending from unconfirmed transactions as input txids are not signed. The author hopes to start a new "testnet-L" similar to testnet3, with this sighash type so that malleability mitigation can be tested out.