For those who are getting the /dev/system error that locks the nand. I was able to get it boot from the nand by loading 7.95 beta 6 and running 'installtointernal' twice. I am using a ott mxq 4k pro. I used the experimental dtb and on the boot from nand I initially got the 'can't access tty; job control' but after power cycling the box it booted fine. I have not tried going back to the original version though.
It works and it's possible to back ti 7.0 .3.012G
Tnx