Thank you for your helpful comments.
I have no ambition to teach youngsters, or to be involved in the competitive dance scene, but to teach and promote social dancing, so my expectation is to work with mostly people in middle age or the active retired (it would be nicer to see a wider age range in the social dancing community, but I can't change the way things are...).
I would be interested to read any other comments, particularly from anyone who might have qualified in recent times under the current IDTA Modular examination system.