SimpleX even has its own mechanism to hide IP addresses since a recent update. So in theory you shouldn't even need Tor https://image.nostr.build/ef5989953f8020bdaf9dccf336265ca59e18186617ab40e0f9071f378129856a.jpg
Oh nvm, it seems like its only for files, not chats iiuc.
You need tor to connect remotely to your own servers