What do you mean "watching the same liquidity providers turn up round after round"?
Once a UTXO is spent in a coinjoin, it's identity is gone. You can't reliably separate the taker's output from the ...
@Kruw you're right that a single round breaks it, my concern is more about a liquidity provider whose utxos show up across dozens of rounds becoming a fingerprint of its own, especially if any of those utxos ever touch a kyc'd exchange elsewhere.