Roffa
I think that was a very clear explanation and certainly it is my experience.
There is one other point on the same topic I would be interested in views.
Sometimes ones hears an aircraft asking for transit being told to standby, remain outside etc. From the pilots point of view this gives no indication of whether (or not) a clearance is going to be forthcoming and if it is, how long the wait might be. I have even heard and had on more than one occasion another request to standby 10 minutes later when asking how the clearance is coming along.
So my question is could controllers not respond with something more along the lines of, remain outside CAS, your onward clearance expected in x minutes, or remain outside controlled airspace, it is unlikely we are going to be able to accept you. Either would be a great deal more informative and enable a much earlier decision to be made as to whether to take up an orbit, slow down, or go around. I think it is something pilots would really appreciate, but maybe there are good reasons why it is not possible?