LJZ01H with 5.1.1?

Hello,
I recieved yesterday my urbane and so far I'm loving it, but I have a question and would like to know if someone knows the answer.

My Urbane came with android 5.1.1 but the version is LJZ01H and it doesn't find any update.
Searching the internet I don't find much information about that version.

Will it be safe to sideload de LDZ22D or should I sideload the LJZ13E before (If i could find the rom)? and what will I benefit from it?

Thanks,
Xupamki