Which guide or tutorial would you recommend to connect XU4 Odroid to Matrice 100 ?
We are working hard to make a new FlytOS release with support for DJI M100. It should be available by next week. I might try to send you a temporary beta release within a couple of days if you are interested.
You can follow this document to get beta access of FlytOS integration with DJI A3/N3/M100/M600.
Even though the document is for RPi, if you use FlytOS image for Odroid and install the debian linked at the document, it would work just fine.