Apart from the initial stage of having lounge access, I can't understand why you would want to spend more than two hours in a lounge, let alone three.
Reading through I started to come to this conclusion myself, why would you want to be in the lounge more than 3 hours unless connecting or delayed. If delayed, I don't think they will come looking for you to say your 3 hours is up and the connecting part needs to be thought out a bit more, especially if the airline does not warn you when booking that the connection of say 4-6 hours only has 3 hour lounge access.