I would think most airlines are using constant-rate descents on non-precision approaches. Most charts in the US have a ROD table based on ground speed whereby you figure an initial descent rate and modify it if g/s changes or a restriction will not be met, using the VNAV information for advisory. (Don't get me wrong, this can be tricky)
Adding 50' to the MDA, you would miss the approach if you were either not in a position to land stably, or you simply did not see the requisite lights or runway environ. Some airlines call it "CANPA". Constant-Angle NPA.
It works rather well in practice. I can't see doing a dive and drive method in this day and age, but I do not know what UPS does or did.