You keep talking about open-source, where can we see these rules publicly? According to whose criteria will certain UTXOs be added to whatever list is being used to determine naughtiness of coins?
Since the coordinator code is all open source, you get to decide your own criteria yourself.
Being open source means absolutely nothing here because nobody has any way of knowing what the actual source code the centralized default coordinator is running.
Here's another idea if we're about to utilize layers: exchange BTC for XMR and XMR for BTC a little while later. Leaves no traces, much better than Wasabi + lightning altogether. You could then coinjoin the bitcoin, just to minimize the blockchain connection with the previous owner.
This doesn't provide you additional privacy since you leave a trace at step 1 when you send your non private BTC to your XMR counterparty.
It does as it successfully breaks the link between the bitcoins you convert to XMR and the bitcoins you get after selling XMR because of the way Monero is implemented.