Yes, but that doesn't address my question. What the UK chooses to allow into its territory isn't the EU's problem. But what goes in the other direction is the EU's problem. They can only solve this by setting up a hard border somewhere, and since they'll have no authority to set it up across the Irish Sea, it'll have to be one against entering the Republic freely from NI, which again is exactly what they don't want.

(In any case, I don't think the UK would allow a free border, for obvious racist reasons.)