nostr:npub1ej493cmun8y9h3082spg5uvt63jgtewneve526g7e2urca2afrxqm3ndrm specifically said in his post:

"The current CTV proposal in BIP-119 has only one hashing mode, known as the DefaultCheckTemplateVerifyHash, which essentially commits to every aspect of the spending transaction in the template hash. From a practical point of view this means that in many circumstances the only available mechanism for fee payment will be CPFP. As mentioned above, this is a potential problem due to it making out-of-band fee payment a non-trivial cost savings in cases where the CTV-using transactions are small."

So he's specifically saying that out-of-band fee payment could be cost savings for small CTV-using transactions.

IMO, you could make the exact same argument for lightning force closures. Even though lightning will move to anchor outputs, which means 0 fee force closures, that will be CPFP'd thanks to "package relay". Those small transactions could have cost savings with out-of-band fee payments. 

But obviously, no one is pushing against package relay. For most small transactions, out-of-band fee payments would be a small cost savings. 

In fact, this statement could technically be true for any pre-signed transaction scheme. Does that mean we should never have any pre-signed transaction schemes? Hardly. 

So, since this issue already exists in Bitcoin and is only relevant to very small transactions, and since CTV can actually decentralize mining even more (https://utxos.org/uses/miningpools/), I'd argue these issues are known, and the concerns with not having CTV are actually a great risk to Bitcoin. Not having covenants, IMO, is a huge risk to Bitcoin custody centralization and people choosing not to self-custody. 

CAT is an entirely different beast, and I agree that the risks are much more unknown. 

https://petertodd.org/2024/covenant-dependent-layer-2-review