Nice post, thanks!

This maybe deserves a full post itself, but let me try ask here first ...

Once you've gone through the setup and learning curve for coinjoin, how do you ensure your spending remains private?

By default in Sparrow with whirlpool your post-mix utxos are recombined when spending any amount above your pool amount setting (e.g. 100k sats). So it becomes much easier to work backwards to find the common initial coinjoin tx, and thus undo all the gained privacy.

Currently I send to Phoenix just the single post-mix utxos to avoid linking, and then gain the privacy advantages of lightning.

But I never see the option to pay with multiple individual utxos txs ? I.e. with BTCPayServer there is a single on chain payment address. Would be great if the default was to pay in a way that the merchant has a single tx for accounting purposes, but chain analysis doesn't have any clue that the payments are linked.

Cc @ODELL @Sethforprivacy