Hello @Omar ,
thanks you for your question about Microsoft supported IoT Edge solutions.
Regarding Azure support tickets, I have only encountered questions from Microsoft regarding the tier 1 supported operating systems.
The OS versions seen there feel a bit deprecated, these are not the latest (LTS) versions anymore like Ubuntu 20.04 LTS.
Also, EFLOW (Edge for Linux on Windows) is not documented there.
Especially Ubuntu 20.04 LTS support is recently announced.
Whether your device is certified or not, you can always submit question here or you can submit issues and feature requests at GitHub.