Lol, I have run a SimpleX server. You can definitely track people if you are the server.
Discussion
Jw, can you possibly expand on this? I know nothings truly perfect, but I'm curious to know how? Thanks in advance
You can always connect incoming requests with IP and IP with location. You can see who is starting channels, who is participating on which channel and if you use the same server across many contacts, the server can link all of them together. SimpleX says in their own spec that each contact should use a different server. But that is never true in practice. 99% of people just use the same default servers. So those servers can see everything.