I have a Nokia Lumia 1520 on the Insider Release Preview Windows 10 update, and was wondering if there was a way to do a "Full System Image Backup" on the device. I doubt the normal phone backup option saves every single setting onto OneDrive. I keep Full Backups of my desktop and Windows 10 tablets on an external hard drive, which I must say gives me peace of mind. It took me a long time to setup my Lumia 1520 to the way I wanted it, specially with all the background settings that Windows 10 Mobile has. Some of the background settings were useless to me, so I disabled them and I\’m saving myself some battery life right now.
Unfortunately no. I do know it can be done on (probably rooted) Android and old Palm OS, Windows Mobile (pre-WP7) PDAs and phones. but not W10M.