In my real plane I have dual GTN650s. When I enter a flight plan in the top device it automatically copies the data to the bottom device (crossfill). It would be great if that functionality was available in the simulator. I see the crossfill button on the RXP GTN650 system setup menu, but it is greyed out and not functional. If anyone knows how to create that functionality in X-plane please let me know.
Otherwise.....RXP, wouldn't that be a nice feature for your next update?