Steve, your concerns and assumptions are well founded.
Adding to those, consider the way in which the simulation is used. For the mandated ‘check’ of a GA below DH due to loss of visual cues, many crews only experience the simulated visual scene being set to zero RVR, which a simplifies (forces) the decision. Whereas in reality the visual scene may slowly reduce, suckering a pilot to continue in reducing conditions, where the decision to discontinue the approach is complex and requires experience.
Whist the ‘misuse’ of the simulation provides the regulated check, it provides no opportunity to experience and learn of the difficulties in making a GA decision in variable visibility – training does not reflect actual operations.
Another issue is that with the advent of the JAA, many of the European operating minima were harmonised to the lowest limit allowed by the national authorities. At that time, precision approaches were ILS, where the minima were based on high accuracy beams minimising the need to manoeuvre below DH.
More recently, so called precision approaches with lesser, but acceptable approach accuracy (guidance and /or displays) have been authorised to the same limits. These approaches may expose crews to rare and possible not-trained-for conditions which require manoeuvres below DH. The visual cues required for manoeuvre differ from those for landing straight-in, both for visual segment and content of the visual scene. Some of these aspects also apply to non-precision approaches.