Mass Flash on with connect tech carrier board

@JerryChang
are there any differences in using the nvmassflashgen + nvmflash with connect tech boards?
will it do a custom image deployable to other production connect tech devices if using the nvmassflashgen, or necessarily using the flash.sh for cloning the app partition for further use with nvflashmassgen -r or without nvmassflashgen will be required?
With multiple continious attempts I am observing the situation when nvmflash completes successfully but the jetson unit doesn’t boot or show any outputs after reflashing with nvmflash
only flash.sh restores by flashing in a workable way but it has a bunch of remnants if using it for restoring to other devices