Classic Duplicate decision play in a safe minor contract or 3NT? If 3NT makes it will be a top if not a bottom!

North will open 1♦  

East will pass

South will bid 1♥ 

West will pass, having thought before South's bid of 2 or 3♥ 

North will bid 2♠ showing a strong hand with longer ♦ s, 1♠ is not a reverse.

South will either show ♦ s or bid 3♣ fourth suit forcing.

Over 3♦ s North will look at a slam in ♦ s

The problem with Blackwood is you are likely to get too high in a minor if partner has too few Keycards.

So over 3♦ North will try a cue bid (do you play 1st round controls or 1st and 2nd round controls).

North starting with 3♥ is south may bid 3♠ and then North bids 4♥ denying a ♣ control so South would then bid 5♦ 

North could lie and start cue bidding with a bid of 3♠ as he is only looking for a ♣ control. South will bid 4♦ denying a ♣ control.

With this North will bid 5♦ 

Over 3♣ fsf  is looking for NTs, but unable to bid it himself. North has a difficult decision 3NT with Q doubleton or perhaps 3♦