My solution was to make heavy use of labels at GH, the "needs more info" and "feature request" ones are obnoxious colours. Second to that, I bought a TextExpander licence, and setup a bunch of macros `notanissue` which expands to:
> Closing because I’m not sure this is an issue, if you are convinced that this is really a bug, please feel free to re-open the issue and add more information (your versions (Ruby, Cap, etc), your Capfile, your logs, and relevant sections out of your Gemfile) > Otherwise support is done via the mailing list (https://groups.google.com/forum/#!forum/capistrano) or at StackOverflow (http://stackoverflow.com/questions/tagged/capistrano) with questions tagged `capistrano`.
And a number of others 'contrib' for contribution guidelines when a PR is in conflict with them, etc.
It's helped lighten the load a lot, and now tend to invest heavily in grooming the issue list, and keeping things neat and tidy at GH. I dare guess, when I'm awake 90% of the issues are classified, or closed within 5 minutes of being opened, this has helped a lot with the feeling of pressure and constant nagging with which I've previously suffered.
Of course, maintaining a large project is a burden, but it comes with career and profile benefits.