Some replies from the Italian (Naples) school of control-bidding:
mw64ahw, on 2022-August-10, 02:03, said:
There are a few style questions that may be pertinent: to 2/1 continuations
1. Is 1♥-2♦ 5+. If so then is 1♥-2♣ GF 2+♣ when 4342?
Yes and Yes.
mw64ahw, on 2022-August-10, 02:03, said:
2. As others have identified there are a number of ways to play subsequent to 2♣. I'm in the camp that shows a minimum hand first (a catchall) and shape 2nd or an Intermediate+ hand together with shape.
...
It doesn't seem to me that we do anything particular subsequent to 2
♣ as opposed to (say) 2
♦: a "raise" to 3
♣ by opener promises 4 cards and a non-minimum hand.
mw64ahw, on 2022-August-10, 02:03, said:
3. The 3♥ bid is good with the point range OK for a semi-balanced hand, but you may need to reconsider for unbalanced/balanced hands if the 3♥ bid is still used as SI.
For us, responder's rebid of 3
♥ fixes trumps, shows slam interest and requests a control-bid.
mw64ahw, on 2022-August-10, 02:03, said:
4. With Italian cue-bidding after 3♥ you can use 3♠ to show the 1st/2nd round control.
You not only can but
must bid 3
♠ if you have 1st or 2nd round control.
mw64ahw, on 2022-August-10, 02:03, said:
5. What does 3NT mean after 3♥? Some use as serious/frivolous. I use the bid to show a weak trump suit. Some pairs also switch the meaning of 3♠/3NT.
Non-serious. It is technically better to switch, but no current partner is willing and it's a notorious forget trap.
mw64ahw, on 2022-August-10, 02:03, said:
6. Is the 4♦ bid necessary to show a control? Either bid 4♥ to deny or move above to continue the slam investigation. Some use the bid as Last Train, but I'm not a fan and use it to show a ♦ void.
A first/second level control-bid just like any other.
mw64ahw, on 2022-August-10, 02:03, said:
7. There are other alternatives to 4NT RKCB. If d) is used then 4♠ as Kickback (keycard asking) or 4♠+ as Kickbo (keycard/control showing) are alternatives. I use the latter as it provides additional space to establish the presence of Kings/Queens etc. when looking for the grand.
With beginners we always allow breakout from the control-bid sequence to 4NT RKCB, otherwise breakout is possible only by a player who has not yet made a control-bid, or not at all (4NT is always Turbo). Some national level players switch the 4 level to bid Turbo below 4NT in a manner analaguous to kickback for RKCB.
mw64ahw, on 2022-August-10, 02:03, said:
8. As others have identified; where is the Queen ask?
I play that 5NT in a control-bid sequence denies the Queen, which works fine when a grand is in the picture (often too high otherwise).
mw64ahw, on 2022-August-10, 02:03, said:
9. Also more considered control bidding after the keycard ask/show may land you in 7NT rather than 7♥.
Exactly, although it needs some care where partner may be bidding a shortage rather than honours (N might bid diamonds late in the sequence to show 3rd level control, for instance). But in this case it still should be easy to count 13+ tricks.
A fundamental style question you do not mention is "do we show controls that are already implicitly disclosed?". My own answer is Yes for controls that are implicit in the auction before control-bidding starts (except for a singleton already splintered) but No for controls that are implicit in the control-bidding sequence (because one continued after the other denied or because Turbo implies the Ace).