It looks to me like the best phone $80 can buy I spent couple hours trying to figure out how to enable Multi User module.
My understanding is that adding this to /system/build.prop would bring users module back:
None of the commonly used apps can root this phone.
Without root I cannot remount /system to read-write to edit build.prop
Stock recovery can mount /system
There are options in recovery to run update from sd card or to update via adb sideload but the phone does not show in adb devices while in recovery. There is also fastboot option.
I also tried dirty cow exploit but it fails with "only position independent executables (PIE) are supported"
I am into this for only couple hours, so I know I am missing a lot. Any pointers that could get me closer to enabling Users module would be welcome.