Sjors Provoost on Nostr: There's other breadcrumbs that can be followed even if they somehow mix coins ...

There's other breadcrumbs that can be followed even if they somehow mix coins perfectly. The long chat history might reveal their native language, and communication style can be compared with others. They also used some sort of service to peg out IIUC. And they seem to have ego and a bad temper, so might make the mistake of bragging about their wealth in the wrong place and time.