I doubt we could find a single answer that would be helpful to all the questions with "have" compared with "have been" in them. I think the consensus was that it isn't very helpful to direct every question about perfect constructions to the canonical post on the subject and I don't think it would be productive to try to close all questions about some subset of that post as duplicates. The perfect in English is really hard to understand. I do think we can identify some good duplicate targets for frequently asked questions of all sorts though.
One way to improve the situation is to group those questions with a tag so it is easier to find relevant duplicates and related questions. We have a number of "-vs-" tags, like past-vs-past-perfect and past-vs-present-perfect. Not all of them have good descriptions and we can't expect the person asking the question to know which tags they should use though.
Adding a good combination of tags makes the "Related" questions in the sidebar much more relevant, which could head some duplicates off at the pass. I know most people completely ignore tags, because they aren't very useful in their current state. If fewer folks ignored them when editing a post, maybe they would be more useful.
