I prefer 2
♦ by East, though I don't mind 2
♣ at all. Once 3
♣ shows the fit, you have Clubs as trump, so I side with East. Of course, I prefer that 4
♣ in this context be invitational, and 4
♦ as RKC for Clubs, since in theory you have denied a Diamond fit.
I do use one gadget, over 1
♦-2m (inverted), that 2
♥ is either a minimum balanced NT, or 15+ HCP with 4 hearts. 2
♠ is a transfer to 2NT, partner breaking it with extras. Here, I use 2NT by responder to show a slam try, usually balanced, but definitely wanting to play it. The other bids I came up with, they might not be optimized so if anyone has better suggestions, please let me know. I think maybe after 2NT, it should be forcing to 4NT, or that partner can bid on over a 3NT sign-off with a max and 5-6 controls.
On a side note, I really need some way to do 6-card RKC (when we have 8+ card fits in both minors), especially in a Precision context.
"It's not enough to win the tricks that belong to you. Try also for some that belong to the opponents."
"Learn from the mistakes of others. You won't live long enough to make them all yourself."
"One advantage of bad bidding is that you get practice at playing atrocious contracts."
-Alfred Sheinwold