Oh, did we recently expand those fields by ~100k bytes too? Quick answer: LN commits- No (those fields have to be there) OTS- No (also mischaracterized description They hash their message into their transaction ID, the ID length doesn't add more data) Samurai- No (a transaction to predicate, another transaction is very common, like a deposit) Taproot- yes It's not that hard to determine: is data being added to the txn that would not be necessary for the same transaction to be spent?