PX4 how to dynamically reroute flight while in flight?

I am using PX4 SITL jmavsim and a custom application using MAVSDK interface to communicate with PX4 sim. Assume I have uploaded a mission and sim is in flight. En-route, is it possible to dyamically re-route the flight to a different mission so that it will continue from its current position and pickup new mission? This should be done without bringing down SITL and not restarting over.

This is super easy to test in SITL and I would encourage you to make a quick test using QGroundControl and jMAVSIM, but it looks like as soon as the new mission is finished uploading, and pending feasibility of the new mission, the old mission is abandoned for the new one.

Thanks @rroche I will try this and update back my results. You may close the other posts, sorry about that.