in order to be able to restore sdcard dd image it needs to be taken from the entire disk, not just from the single partition:
mmcblk0p1
mmcblk0
otherwise mmcblk0p1 could only be restored as a single partition through mksparse/flash.sh method to the sdcard that has already been flashed with exactly same Jetpack version related to the source jetson board used for the image creation
Regarding the e-con
They have a simple-deployment image with drivers integrated, but it is of obsolete Jetpack version.
So the only way to get drivers with the latest Jetpack is to “patch”/upgrade existing OS with adding drivers.
Once the driver support is implemented it could be cloned so that the image will have the driver added.
Finally,
It is possible to restore sdcard image from nano itself, but it requires to use sysrq triggers/ magic keys to halt disks, so it is more handy to do it from sdcard reader