I was trained by an organisation on the south coast. I was told to always ask when go beacon outbound, regardless of "cleared beacon outbound" or "maintain (a level)proceed outbound". At the time i just wanted to get trained and into employment.
I consider myself to have a professional attitude to my work, and consider those in ATC to be professionals. I now only ask if i have cause to need clarification. I feel i was wrongly trained, and that the training organisations are helping to contribute to the confusion.
That said, ATC are the main cause for the confusion. If they did it correctly and consistently this whole scenario would not be contributing to RTF congestion.