Well… Honestly it would be amazing if this unspecified behavior could work for negative values as well as it proved to be really useful. 
I am also confused with 's answer which indicates that this behavior was meant:
The positive value seems to be acting as intended. once you reach ~2.1 billion it is shifting the world origin to the new location, which would put you on the negative value because it is moving the origin and sky sphere to a new location ahead of the player, which is why you see the negative values but returning to 0 does not show your static mesh. 0 has become an entirely new location that is still heading in the positive direction.
Which is completely the behavior we are seeking as this int value is ridiculously small for what we need.
It also seemed to be a bug for the negative value:
The negative, however, is not reacting as it should be.
On the other hand, Adding space wrapping manually will be a “pain” as we have to divide the the space in virtual cubes and keep an array up to date to know in which cube we are… But this would not be enough as the 0 of each cube in this case would be exactly the same ans this is a behavior we do not want.
If we had to clamp this value, we would be in a case that would make our workspace ridiculously small… 
So right now I am really confused between your answer and 's one…
Cheers