The "hungarian fix" is PROBABLY dangerous for Chinese V880's.
The V880 does have hardware differences (no Home and Menu key backlights as one example).
I think it unlikely that for the large production quantity for China, ZTE would buy but not use extra RAM.
I do not expect there is any extra ram to unlock.
My belief is that the pretend-256 phones were ONLY intended for Greece - a small production quantity, explaining why it was easier to "lock away" some ram than to change the hardware production.
Sending pretend-256 phones to Hungary would have been a mistake. The "hungarian fix" was to undo the mistake.
But for China, the production quantity is going to be very very much bigger than for Greece, so there is no reason to install and "hide" extra ram. It seems the hardware is different, and 'trimmed' for economy.
If there was a V880 which seemed to be totally and completely unable to be saved by any other software tricks, (a "brick"), then as a 'last chance', all or nothing, gamble --- then, maybe, it might be interesting to see what happened.
But on a healthy phone? NO, NO, NO. Don't do it!