The explanation of auto-renew says: "On expiration, new port forwardings will be created. The source port will be chosen randomly.". How will that work with bt client?
Not too sure. Right now I have a 1-to-1 forwarding which will expire later tonight and I have the auto-renew on. I will let you know if the port switches up or not.
Edit: I would not recommend Perfect-Privacy, their autorenew does not work.