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I'm actually really skeptical bout all this. Sounds more like fake stuff. If it was really possible, for all these 3 years it should be very common topic in the net. But it's not. 

I am sorry but "3 years"?
The first 3.3 was launched last year in may. To crack a software you need a few versions so you can compare them, especially if it is not a software you can buy as it is. It seems that the both versions are developed together. The real difference starts with software version 7 which have and another hardware.
I am sure there is a possibility for an update.
I read somewhere that the walk away lock (for pre-may cars) hardware is about 35 Euro but Renault is not selling it as a separate kit.

V2 and V3 also defer in hardware.

In what way? What is different? The differences affect the software?

As far as I know, there is difference in the USBs. My guess is the units with software version 7 are the same as Hardware version 3.

The differences in USB (I guess 1.x, 2.x or 3.x) have a little impact on software. Different USB versions can affect the transfer data rate and/or the charging capabilities.
As an example: windows will work the same on a PC with 2.x USB connectors as on one with 3.x connectors.