Forcing the UART adapter to 3.3v is absolutely necessary to make it work (my post about that).
On my side I'm able to run it from UART but as I have firmware 1.0.84 I don't have ethernet after that 
Xmodem is an alternative to send the backups to the device once booted but then I don't know how to restore it 
I will wait to have FIP image working with ethernet switch of the 1.0.84 and then I will have to find how to restore my backups (Bdata.bin, BL2.bin, Factory.bin, FIP.bin, KF.bin, Nvram.bin and ubi.bin).