GrahamJson, on 2018-December-07, 09:21, said:
Also, I consider south's hand to be just about as good as it could possibly be on the bidding so far. I wonder, would he bid the same with KJxxxx of hearts, say, or without the diamond king? If so then you certainly don't want to venture beyond the four level.
I would expect South to overcall 3H with the hand you are positing, rather than doubling. The actual hand is closer to a minimum than a maximum IMO - 3H and 4D are both forcing on this auction, so South's hand is unlimited.