It appears to me the only playable Championship greens are in RGs? Not allowed in country clubs, and I've never seen them in free tournaments other than the Oakmont qualifier last year.
This means players who qualified for the US Open (not me) and live in a country or state that does not allow skill based gaming (I'm one of those) are at a bit of a disadvantage in next week's championship rounds. They can't practice on Champ greens beforehand while others can.
Doesn't sound fair and square to me.