If it's a Rev H, it's likely legit. Chinese-made ones generally use Rev. F since that is the last board schematic to be made open source on the git. That is unless they modified the Rev F to make their own version of the Rev H (as all the changes are public), but I have not seen that yet.
But in the future, I would buy directly from KRIKzz. Also I think KRIKzz just opened an official Amazon store, but I don't think he has the SD2SNES listed yet.