
The only thing I can think of really is missing out on any of the new in-game story elements that may be presented to 1.0 characters only. Though, I don't personally know how deep that divide actually will be. I suspect that there will be a point where both 1.0 and 2.0 stories converge going by how it's presented so far. So all that would be needed is to research the parts that are different. This might not even be an issue if you don't plan to use the game story, but there may be elements that would be unique to a time-skipped character.
The other thing would be the lack of any tattoo that will be on 1.0 characters. A minor thing probably since some might just hide it anyway. Also armor and such will likely hide it too.
The other thing would be the lack of any tattoo that will be on 1.0 characters. A minor thing probably since some might just hide it anyway. Also armor and such will likely hide it too.