It has been a while since we hear from @tuxuser, but he is back and with nice little update to his previous NANDOne utility, so check out out today at his Official GITHub Project Page which is linked below, and start enjoy playing with your XB1 NAND Flash Dumps again!
Xbox One NAND Filesystem tool
Parses Xbox One Nanddumps for filesystem header and extracts the binary files. It's probably not very compatible and contains bugs for sure
Enjoy! Requirements