It seems others have been able to mount emmc separately. I went as far as getting a connector for the USB header and jumpered the pins. But I cannot mount as a drive on any other system, so I don’t know how you are able to expand. I used the web interface to expand the partition, and while it allows this, it doesn’t run fsck or anything after rebooting. Were you able to boot off the sim card or usb drive? It seems I could change the boot up script for that, but didn’t want to make a single change yet. thanks.