if you're continuing down a NPA based on approach lights alone, you are already rolling the dice IMO.
Here, there are very few NPAs that have a true Visual Segment, where the visibility minimum is less than the distance to the runway. On any NPA, I would hazard a guess that if following a 3°-ish profile, you will always be able to see the threshold at the MDA if the vis is on the minimums or greater.
Originally Posted by Ian W
the small vertical error margin does make altimeter setting something to return to
True, however at this point the crew would be operating visually on the PAPI and well below the MDA, and the altimeter value would be not a consideration.