I believe i was told around here someday in the past, that Larian can tell easily wich game was moded ... So i presume (feel free to read as: hope) it should not affect statistic so hard.
It would be shocking if they haven't done something to tell modded games from non-modded games. But if everybody is playing a modded game then they don't get as much data on the base game. And they really need a lot of data on that for any statistical analysis to be particularly reliable, I would think.
