It really is supposed to be 20mph all the way into Queensboro Plaza s/b, the timer there only enforces the most sensitive area of that stretch of track, which is the trailing point switch leaving Beebe.
At the same time, there are archaic speed signs that are around the system at a time when there were particular track anamolies that were corrected or later enforced with timers. One main example that comes to mind is the 20mph into 34th-HSq on the . The little mini 'S' curve has been eliminated and its almost perfectly straight. But the speed sign is still there, and now is prime radar gun fodder (under the follow directions, even though they are technically pointless, law). While there is a switch at the other end of the station, it is far enough outside the station (almost 300 feet, 13mph switch) that the speed enforcement no longer should be there, or at least raised higher (30mph really is correct, I know they dont want 's on the post down the hill into 34th anyway). Another example is right on the track next to it. It used to be 25mph into Herald Sq against the wall on 2 track. As many of you know, there is a GT20 two shot in the station in that location now (since T/O's often ignored the speed restriction), but the 25mph still exists.
Another one that sticks out in my mind is the curve onto QBL from Hillside on the . There are a couple of two shots at GT25 (they clear at 21). The original older speed sign of 28mph is still there. Going north, the same curve is 30mph.