I didn’t know where to put that, too small for the wiki. Nice thread, I wish it keeps growing!
Privacy
TLDR: To maximize privacy, coinjoin pre and post sending to or withdrawing from Bisq wallet. KYC can’t be undone.
A Bisq trade needs to use a security deposit that is temporary held on a the deposit address (together with trade funds) and that is returned to each of the trades when trade succeeds.
On the blockchain, the security deposit is a link between previous and post trade state, that connects your identity to the funds when KYC BTC are used.
When buying Bitcoin, the origin of those BTC are unknown but now can be linked to you.
Thus, to improve privacy, is recommended to always coinjoin after withdrawing BTC from Bisq wallet. It doesn’t matter if Bisq has been used to trade privacy coins like XMR.
It’s also recommended to do a coinjoin before sending sending BTC to Bisq wallet, specially if the BTC were obtained through a KYC exchange. But remember, once you have done KYC, that can’t be undone. The exchange will always know your KYC data and wether you bought or sold BTC.