Sorry but this is wrong and it natively supported in the last release as I beta tested it for DJI. Also this is why I specifically added it to the Wiki as working.
Here is the video I made showing it working and how to set it up. https://youtu.be/6tCBVynN8EI
There is also at least 2 threads on this forum of other users using it with out issues in Mavlink.
Here is one of them where the user was having issues but he had not updated the firmware
The only bit that does not work correctly is the GPS layout if I recall.
While Alex addition means it works natively with MSP Mavlink works fine on the original RE system.