it’s well known and I de done it many times.

if this is being applied on a route basis, without regard to what was available at the begonning, in means you’ll almost never be able to change anything on that route, regardless of whether you needed married segment logic at the time to book the connection, or whether individual segments are available. Because likely there is ZERO additional award availability on the segment you already booked as an award and want to keep.

And I don’t believe AAs IT department is capable of introducing it on an individual ticket basis, where it knows which of the segments on an itinerary were stand alone available and which were married segments.