John, reap what you sow! I have never advocated using DH to achieve the minima on a QNH approach! It is you who needs to read posts more carefully.
Ther is no ILS in the world with a state minima of 200 feet height above the threshold that would put you below that height, anywhere on the approach provided you are on the glideslope. That is made clear in pans-ops.
However, you are permitted some glideslope error at DA, accepting this at DA you may well be below 200 feet height above the threshold.
In modern helicopters fitted with a reasonable AP, coupled to the G/S such errors are eradicated.
All I advocate is that if the helicopter is fitted with a RADALT it is poor airmanship not to use it as the safety device it is clearly intended to be. To effect this it needs to be set below the listed DH minima for the approach, giving a margin to reduce the possibilities of the aural warning before the DA minima is reached. This is the design concept behind the AIRBUS bug system in the EC225/EC175 and it works well in practice.
The ILS systems in Oz do not have significant obstacles in the final approach. If they did the state minima for that approach would be greater than 200 feet DH CAT 1.