WAYPOINT Announcements

[Routemaster]

I like the fact that waypoints can be changed to allow spoken notifications, however after I have changed the waypoint to what i wish to be spoken it is announced immediately after a waypoint I have just passed and not close to when I actually get near or approach it? only the number of the waypoint is announced? considering this could be many miles later it seems pointless,,, can it be somehow changed so that the desired announcement happens when near or at the actual waypoint?
cheers