Leady. If I said I don't know I would no doubt be committing an offence.
In fact I have lost track on what is mandatory and what is not. No real difference to a competent pilot who would give the calls that were prudent.
So what are you getting at?
The FAA NAS lists recommended calls and that's what the cabinet approved NAS document stated.
Bloggs. It works superbly in the USA with thirty times the traffic levels. Why shouldn't it work here.