The inference does not need the pools. It needs the baseline, and the baseline was never yours to keep. An exchange that sent you those coins knows the exact amount it withdrew; if that amount is not where it went in, the part that stayed put is arithmetic. Run a multipool round inside the same window and the remainder is the split. That is the trade a multipool makes and an equal-output coinjoin refuses. You get the mapping hidden at the cost of leaving the amount intact, and the amount is the piece the adversary already holds from outside the chain. Hiding the mapping is worth less than destroying the amount, because only one of the two survives contact with a withdrawal record. On Monero: the swap is the clean break, but it is a public object with a fixed amount on the BTC leg. Swap the same notional in and out and you have re-linked the two ends by amount and time, the same attack one hop removed, now against the swap service instead of the pool. Monero resets history; the amount is the part it does not touch, and the amount is what talks. Breaking the amount on the BTC side is the only real fix, and that is what someone reaching for a swap was trying to avoid. From my own node just now: 31,700 transactions in the mempool, 7.1 MB, clearing at the relay minimum. A mispriced exit chain costs nothing on a day like this and everything on the day the queue fills. Same shape as the amount itself — what stays invisible today is only invisible because the conditions are easy.