Interpreting your question to apply only to hand-picked substacks and be opt-in, I still see a deluge of problems and no benefits. Working through them:
I would like to propose a tick box under a question, that makes sure that during the first, say, 24 hours, no answers will be visible to anyone (except that an answerer can see and edit his or her own answer).
But no one will use this, and if someone does use this, then it almost certainly is a bad question. Questions should be regarding actual, real problems the user faces. Not problems the user might face in 24 hours. SE is not a venue for questioners to mediate discussions on various topics.
Furthermore I don't want to deal with the deluge of questions from users asking why they don't have a solution to their problem yet, and having to muster the sincerity to graciously explain, "Because you clicked the box that says I don't want an answer yet. If you didn't want an answer right now, then why did you do that?"
Even making this opt-in, it's a feature whose accidental and misunderstood uses will do more harm than when users want to use it deliberately, which also is problematic.
Independent answers.
I literally don't see how this is a benefit. SE problems are not and are never brainstorm-oriented. They're problem-solution oriented. Multiple creative solutions or collaboration are not the goal of > 99% of questions on any SE site.
Getting some duplicates, which would indicate some consensus.
No. Upvotes indicate consensus. This is tried and tested. Very, very often the best answer is somewhat subtle or brilliant and upvotes rush in behind it, because upvoters are competent enough to evaluate but not brilliant enough to come up with it. (P v. NP, if you will.)
Avoiding discussion with the first answerer.
No. Discussion includes two things: asking for clarification and pointing out areas of improvement. Often a first answer will have an error that is caught by someone else who might have thought about answering. Users who opt-in to this feature will be hurting themselves here without even necessarily realizing it.
No "authoritative" or massively upvoted answers one feels one has to battle with.
There are two problems with this. Firstly, it's wrong. If the highest-voted answer is not useful to me but the second is... I just have to scroll down the page very slightly more. The first answer is not some video game boss standing in the way
If that is a problem one experiences on an SE site then the SE site is rotten and needs to be thrown away.
Secondly, we want that authority. Firstly, for the utility of future visitors. That is a big part of our mission; to create a long-term repo of Q/A. Secondly-secondly, for exactly the fact outlined above - to indicate consensus.
It would encourage answerers to be more diligent about their answers
Wrong. Downvotes do that. Peer review does that. Obscured answers will do the opposite.
Even limiting to math or physics and even making it opt-in and even exposing the answers to the questioner earlier, I still don't see any benefit; just a bunch of consequences that deteriorate the quality of our site.
Furthermore -
- if you implement this so questioner has pre-emptive access evil information can be planted without review for an hour. A bigger problem on SO where an attacker can literally convince the OP to inject attack code.
- Poor coverage across all questions, too much duplicated effort
- Questions that are 24 hours old tend to already be in their "long term / historical value" stage.
- Duplicated questions in the 24 hour time period that we can't do anything about since the answers are privatized until then
- The benefit of this is totally unclear to the vast majority of users, who want answers now, not to tap into the benefits you perceive (and I disagree with)
- Does not scale to less "close-knit" communities where the majority of users want answers now and fast