If the coordinator could detect you mixing 2 UTXOs at once, it means the coordinator has deanonymized you
Discussion
So who the hell would know if 80% of Whirlpool liquidity was controlled by one entity. Sure it might cost but once it’s in they can remix those forever and imagine the returns they could get…
You're right, that's definitely a possible attack vector (besides a malicious coordinator, who can just do that by only paying miner fees).
I never thought of that. But still don't understand how allowing more than 1 utxo being remixed per client would sove it... Sounds like it would just make it easier to attack