I'm still running android 4.2.2(no otas) and I was wondering if root keep works in this device.
Sent from my XT1058 using XDA Premium 4 mobile app
You mean if you upgrade?
If you have an unlocked bootloader, yes, you can root and disable write protection no matter what ROM is on your X.
If you can't unlock your bootloader, then you are safe to install 4.2.2 with camera fix update, or 4.4 update. You can continue to use SlapMyMoto to root, and MotoWPNoMo to disable write protection.
BUT DO NOT install 4.4.2. If you have rooted with SlapMyMoto/MotoWpNoMo and take the 4.4.2 OTA, you might keep root, but will lose the important Write Protection Disabled that MotoWpNoMo gave you, with no way to get it back. When Write Protection is enabled (the phone's default state with locked bootloader, or the state you are in after you take the 4.4.2 OTA), any changes made to /system, or the like, (including, but not limited to, App installs, file modifications, deletions, renames, etc) are not permanent and are lost at power off/on.
SlapMyMoto doesn't work on 4.4.2, and at this time, no new working root exploit and process has been released. And part of the 4.4.2 update patches the exploit that MotoWpNoMo used, so it wont work.
The 4.4.2 update also updates the bootloader which will prevent safely being able to downgrade the ROM version on your phone. If you try to flash 4.4. or lower, you will either brick your phone, or get it in a state where you will brick when taking an update.