This is where CONTRIBUTING.md comes in. If a project doesn't want Issues to be used for support, then it should mention it there. Whether people actually read it is another story :(
"GitHub issues are for bugs / installation problems / feature requests. For general support from the community, see [StackOverflow](link)"
However, we still get plenty of issues filed that are more appropriate for StackOverflow, so not sure there's anything technical you can do without integrating more closely with StackOverflow :)