Why does the "duplicate question" close reason restrict to Robotics SE only?

Question

If a question is a duplicate from another StackExchange site, when you try to close the question as a duplicate, it only allows you to select the duplicate question from within Robotics.StackExchange. We often get duplicates from Electronics, Arduino, RaspberryPi, and Engineering. So it would be great if this restriction was lifted.

For example, I wanted to close this question as a duplicate. But I had to choose the "Off topic - Other" reason and enter the dupe link in a comment.

The consensus from this other question about the same topic seemed to be about migrating the question. But what if it is already cross-posted? Should we still flag to migrate?

Answer 1

The short and sweet answer is - because, while we're a network of sites, each site is an island and there's no expectation that questions can or should only be answered on one site. In fact, if a question is in scope for two different sites, there's no reason* the question shouldn't be answered on both. There may be slightly different areas of expertise that will create rich answers on both sites.

* So, technically, there's one reason - we don't like it when one user posts the same question on more than one site - "cross posting" - but this is more of an exception. We prefer that a user choose which site to ask their question or, if the question can be reframed to specifically address concepts that each community can address. This is discussed in this Meta Stack Exchange question and its answers.

In the end, if the question is on topic and wasn't a case of the same user mindlessly plopping the question on several sites - don't close it! If it can be a valuable resource for the people using this site, let it exist here, too.