Once the GS is captured there are only two choices. Down or Up. There is no leveling off.
At what point does the ILS Procedure end?
We must assume you are using the criteria of the Pilot gaining adequate visual reference to allow for a decision to land as being part of the definition.
DH is the height above ground that the Pilot must declare his intention to land or go around....right?
In reality....it is far more common to make that decision well before DH if the existing weather conditions allow for an "early" decision.
I am thinking you are failing to understand my post where I described the Sperry system being able to fly the aircraft at a fixed height down the runway as being part of a legal IFR procedure....which it certainly is not.
The point was demonstrate most helicopter autopilot systems can provide better flight performance than is allowed by the Authorities.
In extreme cases....which sometimes we find ourselves in for any number of reasons outside our control...we might have to exceed those legal limitations to safely land the aircraft.
Knowing what your aircraft is capable of doing...and knowing how to use those capabilities might just save your Bacon when you need it.
As to all the jabber about aircraft attitude changes....again...knowing how to fly the machine is a good start on understanding what it is going to do when you move the controls.
If you set the aircraft up in a minimum safe airspeed configuration before intercepting the Glide Slope....(I used 60 Knots IAS)....upon intercepting the Glide Slope (I never had an autopilot that controlled the power) you reduce the Collective Setting to maintain the Glide Slope)...pitch attitude changes were minimal and only transient.....you certainly did not wait for the nose to dip upon intercepting the Glide Slope.
At the bottom....you had to increase Collective slightly to stop the descent and the autopilot took care of the Pitch Attitude changes needed to maintain that same IAS.
The key....is thinking outside the box...practicing the "new" procedure to see how it all works.
Nothing unsafe about it....and it adds another Tool in your box you might need to drag out and use some day.
When you fly in areas that can be invested by Fog over very large areas and see your planned but well distant Alternates go below minimums with scant notice....you start thinking about these kinds of things.
There are no helicopters in Orbit around the Earth....thus at some point you must land....no matter what the weather you find yourself dealing with.