It seems that under specific conditions you can go dto from an already existing flight plan, and select any of the waypoints while keeping the flight plan on screen. I’m not able to duplicate this scenario on demand so I will be doing a bit more testing to figure out under exactly what conditions this works. I’m also thinking that you wouldn’t have under normal conditions both a dto with a flight plan so that may be why a flight plan would disappear once you engage dto…need to do more testing!
But if you have a flight plan already setup all you need to do is select whatever waypoint you want to jump to and activate it.