Migrating questions from StackOverflow's [substrate] tag

Question

For the last 3 years or so, we have used the [substrate] tag on StackOverflow to provide support to our community.

With the creation of this Substrate dedicated StackExchange site, we would want to move many of these questions over to this site, and ultimately clean up our footprint on the StackOverflow site.

One of the questions / answers I had copied over here has been deleted:

Original

New

I would like instead to delete the posts on StackOverflow and keep the post here.

@jnat can I work with you do to this? And for other posts as well?

Answer 1

As was noted in the comments, this has been requested on other sites previously, and it is not a procedure we do for new sites. Robert's answer here covers most of what I'd cover, so I'll grab the relevant bits and put 'em here in context:

Unless those questions are deemed off topic on those other sites, we have no cause to remove content from another site and the reputation/ownership that goes with it.

(...)

Essentially, we would be loading this site up with a lot of questions asked and answered a long time ago… without imparting any of the benefits of reputation, ownership, or experience into the community that is supposed to take care of it.

Additionally, it is also technically impossible to migrate older questions, as noted in this Meta post:

Only questions which are less than 60 days old can be migrated; this rule also applies to moderators.