Procedure tested onda V972 v 3.0 and v 3.2_v1 on Android 4.2.2

To enable multi-user IT TAKES:

• Install "ES File Explorer"
• Open "ES File Explorer"
• Select Tools Root Explorer
• Select Mount R/W
• Select the permissions R/W on /system
• Now open the file /system/bulid.prop
• Go into edit mode
• Append at this file    fw.max_users=4

Note: Make sure the bottom of the file there is a blank line

• Save the change.
• Reconfigure permissions R/W for /system
• Reboot system

Now in then settings on tablet will find the menu when you can enable other users

when creating the user, the tablet performs a partial Rebbot, and on the startup screen appear the various users enabled.

note: might be interesting to have this setting already on the rom arctablet