Since 3NT was suggested by the UI, I disallowed it and adjusted to 4
♥, This is cold off, of course, but
♣K lead seemed very unlikely, and a
♦ to the ace and a low
♣ back also pretty unlikely. However, the play is not too obvious either, so I decided on a weighted score of 4
♥ making most of the time, going off occasionally.
North appeared to understand the UI problems, unlike South, and agreed it should be adjusted, but said he thought his partner would possibly bid 3
♠ over 3
♥ since she would not know he had six hearts or a good five. I realised that my consultant and I had overlooked this point, apologised, and went off to re-consider [and growl at my consultant!]

.
I do not agree with people in this thread who think 3
♥ shows very good hearts particularly, nor did I believe 3
♠ was disallowed, so eventually I ruled
40% of 3NT +2, NS +460
+ 45% of 4
♥=, NS +420
+ 15% of 4
♥ -1, NS -50
Both sides seemed happy enough.
1♥ 2♠ 3♦!
P 3♥ P 3NT
P P P
Result:
3NT/S +2
NS +460