After I FINALLY received the eDIPTFT dev-kit today and a few missing cables arrived too, it was all wiring it up and getting them to talk. With the help of the drones-discuss list, I quickly fixed up a simple MAVLink parser which just pulls the coords and sends them to the display in terminal mode.
Now, the fun part starts - develop a nice UI and implement some meaningful features.
The eDIPTFT43 display, by the way, is incredible! If it hadn't anti-mirror coating and the touch screen, the viewing angle would be +/-90° horizontal as well as vertical. It's nicely bright and the colors are pretty vibrant. I'm gonna write a review on that display somewhen later.