Some weeks ago, I had my first experience in the "dare to declare" tourneys as a substitute. As I sat, I was immediately thrown onto the hot seat declaring a 6!H slam. I had some experience from the 1970s with "par tournaments" which are similar to the "dare to declare" format, so when I saw a club holding of A Q 10 in dummy opposite K 9 8 in hand, I "knew" that it was very likely going to be necessary to take a "practice finesse" to gain an extra entry to dummy and I also spotted that the issue was likely to be a 4-1 trump split needing a trump coupe to succeed. I did not think things out as well as I should have, and needed one of those club entries before actually exposing the bad split. I chose to use the !CQ for that purpose and exposed myself to failure. Now, when I led a small club for my second entry in that suit, LHO could have scuttled my plans by dumping the J in front of the A 10 -- forcing me to waste the A and leaving me no way to overtake the K! That is a rather esoteric defensive move, and LHO was not up to the task -- resulting in me making the contract despite the error.

Yesterday, following another "dare to declare" tournament I started kibbing a team match involving a couple of players I have partnered (but we won't name them here). An auction involving preemptive interference resulted in a flaky 6!S contract missing a cash-able A K of diamonds. But, the honors were split and the preemptor led the Q from his Q J 10 x x x suit.
Dummy produced five hearts headed by the K as well as the ominous A Q 10. Declarer held the singleton A and -- you guessed it, the K x x! Declarer has 6 spade tricks, 2 top hearts and 3 club tricks -- and a very sad looking diamond suit. As declarer draws trumps, our defender slips and discards 2 hearts. This means that declarer can ruff out the hearts and score his 12th trick with dummies last heart -- if only three entries can be found to dummy (drum roll). Declarer leads a small club -- will he try the 10? No, he plays the Q and ruffs a heart. Now he leads his other small club -- can the defender find the hero play of gumming up the works with the J? No, but declarer plays the Ace anyway. And my kibbing time was up!

Stay alert! Watch for a dummy holding A Q 10. If you are declarer and need three entries while holding K x x, take the finesse first. If you are defending and declarer plays the first round to the Q, be alert to the need to jam the works by rising J on the second round.

And do practice those Angle blue hands -- the situations can really arise in real life!

A mentor (teaching walsh responses) specified that after 1 1 , opener should rebid 1 N when balanced even holding 4 spades. I do not find this to be a common treatment (BBO advanced FD card is ambiguous on this).  I liked it because I really like bidding no trump as often a possible (oink oink).  The implication then is that 1 1 1 denies a balanced hand and therefore promises at least 4 clubs (5 unless 4-1-4-4) and you know about the club fit before any 4th suit / new minor / xyz bids.
I would not expect a pickup partner to bid that way. I would expect partner's bids over the 4th suit auction to show 3 card  support before a diamond stopper.
 
In transfer walsh systems, this is even cleaner since opener "accepts" the transfer with minimum balanced hands so:
1 1 ; 1 always denies a balanced hand. But transfer walsh is just not seen very much.