Solo Machines
The simple truth Typerated is the numbers of actual 'solo's' nowadays is very much reduced compared with the 'wood' days.
Even after all the dual (planned) a Cadet gets one solo and then has to rely on getting an 'advanced' course.
The Canadians use very simple metal (strutted) gliders but i am not sure if they are available any more.
No manufacturer was going to make a bespoke aircraft that only suited the ATC and to be fair the Viking has done well in service (they look amazingly fit considering they are grounded)
The whole gliding scenario has been diluted with the advent of para-wings hang gliders and simple powered micro lights.The eye-watering cost of a glass two seater (which are designed to train distance and speed flying) and have fantastic performance rather distances them from the basic ATC requirement.