Yes, the CDA technique resolve the MDA question admirably for those airlines with a '3 deg and go-around at minima' SOP.
When we first had the VC10K, we used to fly the NDB to circle. We'd fly level on reaching MDH, then a 600 ft QFE visual approach. Not that difficult given adequate practice - but later banned beacuse of noise and because we could actually practise it in the new simulator.
Few airlines will have the luxury of giving their pilots sufficient manual flying practice to be able fly a 600 ft a.g.l visual approach comfortably, I would imagine?