How to deal with TeX.SE question that is duplicate of a question on another StackExchange site?

Question

Is it possible to flag a question as a duplicate of a question on another StackExchange site (SE site)? What if the question is closed there as off-topic? For example, see this question on TeX.SE and a possible duplicate on SO where this answer is answering both questions.

Migration of an old question to TeX.SE will spoil the view counter on TeX.SE and give the question a wrong ranking (see Policy on migrating questions from another StackExchange site?). So it seems not an option.

Then there is quoting. One could

1. post a link to the old question / answer, or

2. quote the most appropriate answer literally (that is copy and paste into a quotation block, add the link, mention the author).

Should one use a community wiki instead of an answer to be fair?

To sum up, which technique is recommended in this case?

Answer 1

I'd go with option 2, making it CW. We can have a good answer on our site that would make for easier browsing. Migrating the question on SO is out of the question, I'm afraid, since it's quite old.

Answer 2

In this case, in my opinion it makes sense to migrate the question from SO to TeX.SX, polish it by removing the not-an-answers and properly retag. The question is good as it stands, so are the (real) answers there. The one here can then be closed as a duplicate (if it is a duplicate, I'm not an expert in this).

IMHO: Migrating good questions with good answers here, if they clearly belong here (which is obviously the case, since SO closed it as off-topic), makes sense and is valuable for the site.