Using the micro USB port (J4) on Dragon Board 410c

Is there any information on using the micro USB port (J4) port? I see it in the SDK development diagrams as connecting the host to the board. But then, in their examples, they say copy the .exe file to a USB drive then to the board.
Seems to make more sense to copy across the USB through J4.
Any one know if this way of downloading is in the works? or any real use for J4?
Also seen a reference that it might be useful if the Android OS is being used. I’m using the Linux setup right now.

The DB410C cannot operate the micro USB and host USB ports at the same time. That means that although you can use J4 for a few things (such as running a private network between the host and board) it is very rarely worthwhile since losing the host USB ports loses too much function.

Also for the Debian image, ssh via WiFi is (more or less) as powerful as using J4 in any case.