DJI were unfortunately giving you bad advice here. a USB-A port should always be on the host device (like your PC or whatever you are connecting another client device to). I'm not sure what this port is for on the smart controller although in...
Remember that APAS is simply a tool to try an help the operator in cases where the operator didn't see some obstacle. But it is always the operator's job to see and avoid. So, if a crash occurs because the drone hits something; #1 it's operator...