Could we migrate or cross-post excellent questions and answers to ELU from ELL? [duplicate]

Question

I think a lot of questions that native English speakers would have difficulty answering get asked on ELL as opposed to ELU. And as a result, many questions get asked on ELU that are essentially a duplicate of a question already asked on ELL. I was wondering if it would be possible to migrate or cross-post these questions from ELL to ELU.

Some questions that I think would be helpful are:

Tense agreement in the past irrealis conditionals

He mustn't / couldn't have been hungry

There are probably similar questions to these already on ELU, but I feel that the sources cited in these particular questions (in the answers and the comments) would be very helpful to those wanting to learn more about modal verbs and conditional statements.

I think that modal verb questions and conditional statement questions are good candidates for cross-posting.

UPDATE in response to @Sumelic's post:

I guess I haven't considered the exclusive interests of each site on this network. I see how migration would harm the visibility of ELL. I'm not so convinced with cross-posting. But I don't really know what goes into a network such as stack-exchange.

UPDATE I think my using the term "cross-post" has confused some people (@Rathony & @Curuiousdannii). I'm not asking to cross post questions to solicit better answers, but to cross post questions along with answers to help people find answers to commonly asked questions, which I believe would reduce duplicate questions. So I am asking to cross post answers but that would require cross posting the questions as well.

Answer 1

Questions should be posted on, or moved to, the site where they are most appropriate. If a question has been posted but it would be more appropriate on another site, it can be migrated. This is subject to the "Don't migrate crap" rule. Poor questions on the wrong site should simply be closed.

There is a grey area where a question is entirely appropriate on its existing site and would also be entirely appropriate on another. This shouldn't happen very often. In that case, moving is discretional: if enough voting members can be bothered to vote to migrate, it can be migrated.

But cross-posting is definitely Not A Good Thing To Do. A question is unlikely to be entirely appropriate in two places. If it is, then it is entirely appropriate in its first location and it doesn't need to appear in the other: Stack Exchange is an ordered repository of knowledge, and the question and answers are likely to be found by those who are looking for them, whichever site they appear on.

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There is a possibility that a question appears on ELL which is a duplicate of one on ELU (or vice-versa). That's OK: answer the question as appropriate to the site it's on. Or if you vote to migrate it to the other site, then a comment to point out the existing duplicate will be helpful: it can be migrated and closed as a duplicate. This requires moderator action because a simple closure will reject the migration.

Answer 2

I would not feel good about migrating these. To me, it seems like "stealing" good questions from a smaller, newer site.

Cross-posting questions, I'm not sure about.

You say

There are probably similar questions to these already on ELU, but I feel that the sources cited in these particular questions (in the answers and the comments) would be very helpful to those wanting to learn more about modal verbs and conditional statements.

In this case, before posting a new question, I would first try to find one of these already existing similar questions, and then post or edit an answer to add these helpful sources. I think it would also be a good idea to include a link to the ELL question: this provides proper attribution, and lets people go read the answers there. If you post a new question, it will just spread things out more and make it harder to keep all of the most useful resources updated and accessible from the same place.