Custom Property when creating a NWConnection

I am developing an App using the Networking framework, which can be either a Socket Server or a Socket Client, such that 2 devices can communicate remotely.

I would like to include the Client's userUID when creating a NWConnection, such that when the SocketServer accepts the connection, it knows immediately which user is connected.

(Currently I achieve this by sending the UserUID in Welcome/Introduction messages, which seems an unnecessary overhead, and because I am using UDP, I also have to make sure these messages are acknowledged, before safely using the connection.)

Is there a way to add this custom data into the NWConnection?