https://petertodd.org/2025/opentimestamps-and-knots-ocean
'Hypothetical: Knots No Longer Relays OP_Return Transactions: (...)
At the moment, no released version of Bitcoin Core or any known fork of Bitcoin Core (Knots and Libre Relay) propagates transactions paying a fee-rate less than 1 sat/vB. Yet, at the moment, both of my Alice and Bob calendars are producing transactions with sub-1-sat/vB fee-rates. Even though something like 99% of Bitcoin nodes reject these transactions, they get to miners just fine.
As Satoshi said in the initial announcement, “[Bitcoin] takes advantage of the nature of information being easy to spread but hard to stifle”.
Since it only takes a single path to get a transaction — information — to a miner willing to mine it, for an actively maintained operation like the OpenTimestamps calendars, it is exceptionally difficult to prevent transactions from getting to miners by simply running nodes that reject those transactions.'