Thank you so much.
So, I have two option:
Start Armbian directly from SD, as you say.
But there's a problem, sometimes starts Armbian, sometimes Android. There's a way to starts only from SD card? Like a boot priority?
Try, with risk, to install Armbian_5.41.1_S9xxx_Ubuntu_xenial_3.14.29_icewm_20180507.img.xz that, if I understood well, has a NAND support, and then upgrade to last release. But it is a decision that I must evaluate with great serenity.
A nightmare, just a nightmare.