SIGHASH_ANYPREVOUT has been designed as I understand primarily for the eltoo channel construction use case although it has [many other potential use cases][1] too. It was stated on [Twitter][2] that the proposed opcode CHECKTEMPLATEVERIFY can also support eltoo channel constructions. Is this the case? The second part of that tweet ("APO isn’t enough on its own for Eltoo") I think is just false unless they are referring to [ANYPREVOUTANYSCRIPT][3]. Jeremy Rubin stated on IRC that CTV commits to all scriptsigs and sequences whereas ANYPREVOUT does not. I'm pretty certain the answer to this question is no, I can't think how this would work using an opcode rather than a sighash flag. [1]: https://anyprevout.xyz/ [2]: https://twitter.com/ProofOfKeags/status/1474780645859762180?s=20 [3]: https://bitcoin.stackexchange.com/questions/107797/what-is-sighash-anyprevoutanyscript/