There's also a benefit to being able to transfer to notrumps.
1♦ (x) 1NT all pass
the lead comes from the weak hand, through our strong hand, and it's in a suit where both defenders have length.
1♦ (x) 1♠ (p)
1NT all ...
Ed, the rules you quote tell us that [i]if[/i] the defenders have a written defence, the opening side can refer to it. They don't tell us that the defenders have to write anything down, beyond what is required by the convention card rules.
I think it's better to play
Double = takeout of spades
Cue-bid = an overcall in hearts
because with the overcall type you're happier to commit to the three-level.
The same applies to most auctions that start
(1 suit) pass (transfer)
"I don't think players can consult other written defenses."
The opponents are allowed to consult their own defence. From the Midchart:
"A defense to a method which requires the above pre-Alert (whether
the approved one or one provided by the opposing pair) may be
referred to during the auction ...
I think there are good reasons for getting rid of the right to written defences to a Multi, but I'm not sure that this is one of them. Nobody forces people to use the book defence, and nobody prevents their reading the defence in advance. Should we really be ...
"I would vote to rescind the stupid policy of forbidding asking when you don't need to know."
There is no such policy in the EBU regulations. The closest they get to this is to say "Players sometimes say, 'I always ask whether I intend to bid or not'. This ...