I would have thought that the best time and place to find out what the controller wanted was to ask him there and then. Read back the bits of the clearance that you understood and end the transmission with "please explain what you mean by one long transmission". Forget Cap413 phraseology, just use plain English. The controller will then know that you don't know what he's asking. If he gets asked to explain often what he means then it will highlight to that station an issue with their procedures that might need to be amended or documented better in AIP, etc. And just as important it will give the pilot a chance to learn something new.
If there is anything in a clearance that you don't understand then surely you can't except any of the clearance.
I know we are talking about a MATZ and theoretically, as long as you stay clear of the ATZ, you don't have to talk to them, but is that really a wise idea?
Regards
Stoney