Switching from EU to US copy?

[Nodnarb]

Hey there, just wondering if anyone knows for sure what happens if you switch to a US copy after using a EU one for a while, will I have to start from scratch? Can't seem to find anything definite online about it.

 

[Nodnarb]

Is there a reason you are switching from US to EU?

Well I ordered my copy from ebay, and the seller failed to mention that it was EU. Didn't think anything of it at first since the switch is region free, then i realized that the splatfest stuff is based on the region of your game cart. So i was gonna return the EU one, but if I start from scratch I'll probably just keep it even though I live in the US. The only thing I can think of that would actually be a negative is maybe having a harder time finding games during splatfests? Not sure.