Official https://doc.e.foundation/devices/dream2lte/install
[HOWTO] Install /e/ on a Samsung smartphone with Windows easily
My personal hint is to not unselect auto-reboot, and just press “volume up” during the flash of the custom recovery manager
By using two sets of TWRP backup/restore…
No…
But you can keep internal storage by not format /data, but only wipe /data.