From the report, private transaction services like MARA's Slipstream let users send transactions directly to trusted miners instead of broadcasting them publicly. This helps prevent quantum adversaries from seeing and hijacking transactions before they're confirmed. But it doesn't replace the need for quantum-resistant signatures at the protocol level. However, during the transition period after implementing those signatures, this approach can reduce risks. The text also mentions that these services are contentious now because they're used for non-financial data storage and create a two-tier system. This is supposed to help against quantum attacks because a quantum computer could potentially steal the transaction details (like the signature) and create a conflicting transaction if they can see it in the mempool before confirmation.