yes. I think anyone from LI on this forum would agree.
I live here, and I agree that there are a number of rural or not too populated places to dump a body on Long Island. Maybe potential dumping grounds are not as plentiful as some other places in our nation like Nevada, Utah, or lots of others. But, there are lots of locations one could dump a body that would have been closer to travel to from Manorville than that beach. I think the killer plain and simply felt comfortable dumping some of the remains at that beach.
If you were to map any generally direct route from Manorville to the beach via the satellite map you would see many perfectly suitable (awful choice of words...sorry

As for changing MO's? Killers sometimes do that for a variety of reasons. The killer can become more cocky and not bother so much to cover his tracks, maybe he developed arthritis so it is painful to cut up bodies. Maybe his tastes changed. Some sk's have different methods of killing and disposing of bodies that they not only change from but go back and forth to. Some shoot one person, strangle the next and shoot the third victim. I do agree that that our gb4 killer is organized at least in part. They are all in burlap and all in the same area, for example.