Is there any documentation on using extended USB port on M2E?Mobile SDK or instructions on making our own extended device like custom beacon?

While on topic is there any way i can power Raspberry attached on M2E? If yes, can i use M2E communication channel to communicate with controller Android app?

I know that Matrice and other development devices might be better in my case but M2E was necessary.

I think it is impossible to make your own device  on M2E. As I know the extended USB port can only connect device of DJI.