I opened 1♣, and partner said ... 1♦! I bid 4NT, if he had 1 keycard and said 5♣, 5♦ is perfect contract (he can hardly have 4) if he has 2 he'll say 5♥ and I can put him in 6♦ (which he did on this occaison). But, if he said 5♦ I would be in trouble cause with no keycards we can't even play 5♦ but with 3 we should be in 7♦, and I have to decide now, I can't make some little bid and get partner to correct it if he had the higher number!
Obviously playing inverted RKCB would work way better (with 5♣ I can bid 5♦ to get him to correct it if he had the 3 keycards, 5♦ I can just pass with his 1 keycard since he can't have 4). Is it just this particular occasion, or does it often work out better in minor suit contracts, to use inverted RKCB?
Also should I have bid it differently just in case he has no keycards and we can stop in 4♦?

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