I don’t think that warning is coming from Map Pilot Pro… It sounds like you need to close all other drone related apps when using Map Pilot Pro.
In the interest of not having aircraft crashing all over the place we don’t provide any mechanism for overriding the aircraft’s RTH procedure. That would be unsafe. It is there for a reason.
The best thing you can do is make sure your battery is properly calibrated and the warning levels are set appropriately in the DJI app.