Bridge in Oz

This one is from the Swiss Teams event of the 2024 Port Macquarie-Hastings March Congress in Australia.

Match 6, board 19. We were vulnerable against not and I held this interesting hand as East:

♠ 864
♥ AKQ109432
♦ 53
♣ --

The bidding proceeded:

South West  North East
Pass  1♣    Pass  1♦*
1♠    2♦    3♠    ?

As we are playing transfer responses to 1♣, the 1♦ call showed 4+ hearts, like a 1♥ response in standard methods. Partner's 2♦ call, being a normal reverse, showed extra values.

I thought a bit about my rebid. Slam seems possible but there's no good way to explore for it. If I just bid 4♥ it seems likely the opponents will compete to 4♠; there's no way I want to defend that so I'll be obliged to bid 5♥.

Therefore why not bid 5♥ right away? In addition to reaching the same likely level, it tells partner that I have slam interest. It's a "free" slam try, i.e. without the normal added risk.

Partner elected to pass and put down this dummy:

♠ 3
♥ 5
♦ AK1064
♣ AQ10963

The defense began with a spade to North's ace and a trump return, so 11 tricks was the limit. It was a push board.