FWW : Original Post?? who ever heard of anyone keeping to the topic at hand on pprune?...sheeesh!.
In any case, I have yet to see any ICAO requirement for a mandatory 2.5nm level segment on the LLZ prior to GP intercept. It is remarkable for them to use a word as strong as: "mandatory". Rather, they are more usually so politically correct that the word of choice seems to be: "reccomended".
Mind you, they do like to surreptitiously change things from time to time.
If this requirement is indeed true, it will come as a rude shock to a lot of people (myself included) who like to fly constant descent approaches in the interest of smoothness (= passenger comfort) and reduced noise.
Consider just how pee'd off all all those voters, living about 2.6 n.m downwind from the nominal GP intercept point, will be. Can you imagine the political flak resulting from the noise of all those engines spooling up at 2:00 am....Hehehehe...
Nope, Sorry, I just cant see this idea working.
However, I await the final word on this topic with bated breath. Hopefully an ICAO guru will post the "final word".